How to run test classes from external folder which is not in classpath with Junit5?

I have an external (not in classpath) folder with compiled test class and I want to run JUnit 5 tests from the compiled class programmatically. But JUnit 5 doesn't see the tests method. The test folder:

The code of Calculator.class:

public class Calculator {
    public int sum(int a, int b){
        System.out.println("HI!");
        return a+15+b;
    }
}

Code of CalculatorTest.class:

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.assertEquals;
import java.io.ByteArrayOutputStream;
import java.io.PrintStream;


public class CalculatorTest {
    Calculator calc = new Calculator();
    @Test
    void sum() {
        System.out.println("test");
        assertEquals(5, calc.sum(2,3));

    }
}

The code of JUnit5 runner:

@RestController
public class TestRunnerController {

    @GetMapping("/run")
    public void runTest() throws Exception {
        ClassLoader cl = new URLClassLoader(new URL[]{new File("/home/admin/test_folder").toURI().toURL()});
        //takes CalculatorTest compiled class from test_folder to start JUnit5 tests
        Class cls = cl.loadClass("CalculatorTest");
        //start JUnit test and prints results of the test
        runTest(cls);
    }
    public void runTest(Class clazz) {
        Launcher launcher = LauncherFactory.create();
        SummaryGeneratingListener listener = new SummaryGeneratingListener();
        launcher.registerTestExecutionListeners(listener);

        LauncherDiscoveryRequest request = LauncherDiscoveryRequestBuilder.request()
                .selectors(selectClass(clazz))
                .build();
        launcher.execute(request);
        List<String> resultList = new ArrayList<>();
        TestExecutionSummary summary = listener.getSummary();
        System.out.println("test results:");
        summary.printTo(new PrintWriter(System.out));
    }

}

When I run the code I get:

test results:

Test run finished after 111 ms
[         1 containers found      ]
[         0 containers skipped    ]
[         1 containers started    ]
[         0 containers aborted    ]
[         1 containers successful ]
[         0 containers failed     ]
[         0 tests found           ]
[         0 tests skipped         ]
[         0 tests started         ]
[         0 tests aborted         ]
[         0 tests successful      ]
[         0 tests failed          ]

I run the program by the followin command: root@box-702307:/home/admin# java -jar myjar.jar

My pom file:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.5.2</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>app</groupId>
    <artifactId>rem</artifactId>

    <version>1</version>


    <properties>
        <java.version>11</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter</artifactId>
            <version>5.9.0</version>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-engine</artifactId>
            <version>5.9.0</version>
            <scope>test</scope>

        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-engine</artifactId>
            <version>5.9.0</version>

        </dependency>


        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-api</artifactId>
            <version>5.9.0</version>
        </dependency>
        <dependency>
            <groupId>org.junit.platform</groupId>
            <artifactId>junit-platform-launcher</artifactId>
            <version>1.9.0</version>
        </dependency>
        <dependency>
            <groupId>org.junit.platform</groupId>
            <artifactId>junit-platform-commons</artifactId>
            <version>1.9.0</version>
        </dependency>
        <dependency>
            <groupId>org.junit.platform</groupId>
            <artifactId>junit-platform-engine</artifactId>
            <version>1.9.0</version>
        </dependency>


    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <mainClass>app.Application</mainClass>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>