You need to be a customer of Tmobile USA and meet the requirements in the link below.

https://www.t-mobile.com/support/devices/unlock-your-mobile-wireless-device

i have iphone 12 pro locked sim 

i need unlocked sim

Are you a Tmobile customer and meet the requirements in the link posed above your post.

Yes, I have a device that is locked to the company's SIM card. I want to unlock it

Do you meet the requirements in the link, if so follow the  instructions.

yes

No one on this forum can help, you need to call to make the request.

How can I submit a request? There is no place to correspond. Can I send their message to submit the request?

Dial 611 from your handset or scroll down to the follow us link and use messenger on the site you clicked on.

I'm not a resident of the U.S. states, I'm out of the country, I want to activate the slide lock, please help me

I can't help nor anyone else on this forum.

You're going to need to find a way to request the unlock code. Only the account holder of the phone can make the request.

If you are not a resident of the United States.  That makes it very hard to meet all of the SIM Unlock Policy requirements and to request the SIM unlock.