Verifying with E-Mail address.
Navigate to your account page, scroll down and click "Verify".
A verification E-Mail will be sent to you. Click the verification link in the E-Mail to verify your account.
Verifying with Roblox.
Navigate to your account page, scroll down and copy the provided verification phrase.
Update your Roblox account's "About me" to only that verification phrase.
After you have done this step, click "verify" on your account page.
Once verified, make sure to remove the verification phrase from your Roblox account's about me