ADB screenrecord command not found

Huawei has removed this cmd tool from /system/bin. Run command adb shell ls /system/bin/ see if you can find this tool from the outputs

First of all, if you have copied this line from command line, then it seems to be spelling-error:

adb shell screenrecord /sdacrd/my.mp4

Should it not be like adb shell screenrecord /sdcard/my.mp4 ?

Are you trying to save this video on your device or on your PC?

Now, to record screen or to capture screenshot, I strongly recommend to use Android Studio as it has inbuilt options to record.

It's here in MacOS:

You need to undestand whe does adb shell screenrecord /sdcard/my.mp4 mean. It means execution "screenrecord" command in your phone's shell. You could do the same by installing any terminal emulator on your phone, run it and type (on phone) screenrecord /sdcard/my.mp4

You are getting "command not found" error, it means there is no "screenrecord" command available. Most devices should have it included, but it seems your device have it missing.

Is there any other way to capture screen except screencap?

In one word: scrcpy

From Wikipedia:

scrcpy is a free and open-source screen mirroring application that allows control of an Android device from a Windows, macOS, or Linux desktop computer. The software is developed by Genymobile, which also developed Genymotion, an Android emulator.

On their Github repository you will find instructions to install it on several operating systems (including Windows, Linux, MacOS) and to run it, with various options to set resolution, bitrate, screen orientation, etc.

Unless you explicitly disable this feature, it also lets you control your device from the PC.

Using the --record option you can save the screen capture on a video, and using the --crop option you can even capture or record only a specific part of the screen.

After a long search, this is the tool I liked the most and that I am using, since there is no screenrecord in my phone.