I want Puppeteer to click a random in-stock size from the dropdown menu on this site:

https://www.shopcapcity.com/product/new-era-exclusive-59fifty-navy-light-blue-anaheim-angels-fitted-grey-uv-very-limited-2/

I can get it to click on the dropdown and bring the in-stock sizes but I can't get it to automate choosing a random item from the dropdown list

This is part of the code I have now

await page.click('#size')
await page.waitForTimeout(200)
await page.waitForSelector('#size')
await page.click('#size', '7 3/8)

What I want Puppeteer to do Is automatically click on a random size from the dropdown that is in stock but how?