It is recommended to submit the in-game account recovery request when you have lost access to your account, @Zack. If you submit an account recovery request and it is approved, all other social media accounts linked to your PUBG MOBILE account will be removed, and the email you provide when submitting the request will be linked to your PUBG MOBILE account. You'll need to log in with that email later using the verification code.
If you have access to your account, you may contact the customer service through your Account settings using the Customer Service option located at the bottom.