Where do you find your player ID on Roblox?
Login to Roblox with your username and password. Or you can use the Quick Login feature. Then tap on your profile picture on top and tap on the URL in the mobile browser. The number will be shown right there.
How can I copy my Roblox ID?
On the Roblox website, right click on a link and select Copy ID to copy an asset or user ID to your clipboard if one exists in the targeted URL.