Below is the code that I had done already to achieve the parallel execution This is the jest.config.js file

 preset: "jest-puppeteer",
 testMatch: ["<rootDir>/tests/paralleltest/**.test.js",],

This is the jest-puppeteer.config.js file

module.exports = {
    launch: {
        headless: false,
        exitOnPageError: true,
        args: ['--no-sandbox','--disable-notifications','--start-maximized','--force-device-scale-factor=1.0'],
        defaultViewport: null,
    },
    browserContext: "incognito",
};

This is the script for parallel execution

"parallel_testing":" jest ",