How to use random and loop in the draw loop in p5.js?

I am trying to repeatedly draw lines that go diagonally across the screen. I am quite new in p5.js, I am not quite sure how to properly structure the random function call, and for-loop within the script to make it happens. Currently it assigns random x and y for startPt and endPt, and seems like it's looping and drawing the same line over and over again. How can it be done so that each loop, a new line with new coordinates will be drawn?

Also, I tried putting the codes to create startPt and endPt inside the draw () loop, but it goes on indefinitely.

const margin = 50;
var loop_num = 100;

var startPt = {
    x:0,
    y:0,
    domain:0,
}

var endPt = {
    x:0,
    y:0,
    domain:0,
}

function setup() {
    createCanvas (600, 400);
    background (0);

    create_startPt();
    create_endPt();

    // re-select endPt if it's not in diagonal domain of startPt
    while (startPt.domain*endPt.domain != -2) {
        endPt.x = random(0+margin, width-margin);
        endPt.y = random(0+margin, height-margin);
        endPt.domain = point_domain(endPt.x, endPt.y)
    }
}

function draw() {
    for (let i=0; i<=loop_num; i++) {
        stroke (200);
        line (startPt.x, startPt.y, endPt.x, endPt.y);
    }
}

// check and assign domain number based on point location
function point_domain(x, y) {
    if ((x>=0) && (x<width/2)) {
        if ((y>=0) && (y<width/2)) {
            return 1
        }
        else {return -1}
    }

    if ((x>=width/2) && (x<=width)) {
        if ((y>=0) && (y<width/2)) {
            return 2
        }
        else {return -2}
    }
}

// create startPt
function create_startPt() {
    startPt.x = random(0+margin, width-margin);
    startPt.y = random(0+margin, height-margin);
    // get domain tag of startPt
    startPt.domain = point_domain(startPt.x, startPt.y)
}

// create endPt
function create_endPt() {
    endPt.x = random(0+margin, width-margin);
    endPt.y = random(0+margin, height-margin);
    // get domain tag of startPt
    endPt.domain = point_domain(endPt.x, endPt.y)
}