I need to unlock my iPhone

You need to contact T-Mobile to request the SIM unlock for your iPhone.  

T-Mobile device unlock | T-Mobile Support

You must be a T-Mobile customer and meet all of the SIM Unlock Policy requirements to be eligible.  

SIM Unlock Policy | Unlock Your Mobile Wireless Device (t-mobile.com)

If you are not a T-MobileUSA Customer and or don’t meet all of the SIM unlock requirements.  Your device can not be SIM unlocked!  

This is basically a user to user forum with some tmobile moderation that don't have account access so you need to contact Tmobile.

Can you help me

 IMEI 35 304011 098518 0

You go to the line the phone is associated with,. there should be an option to check the phones status and if eligible you can select unlock request. This is how I did it with my Pixel 4XL but with my Pixel 6 it was unlocked after 40 days without a request.

I logged in to my account. How do I request the code

If you meet the requirements in the link below your phone will be automatically unlocked, if not you will need to contact Tmobile support to request the unlock code ot you can sign into your mytmobile account and request the code from there.

yes

Are you a Tmobile USA customer?