

but I can only find it t-mobile locked. I can carrier unlock it myself
Careful with that assumption. I bought a TMO-locked OP Nord N200 thinking I could do that but even after using it on my account for a year, they say “it’s not in our system” and it remains carrier-locked. Basically when it hit the secondhand market, it was removed from TMO’s system and they have no record of it and cannot carrier-unlock it (or that’s the story that was told to me by 3-4 different people within TMO).
but will I be able to access the boot loader
Depends if you can carrier-unlock it.
https://service.oneplus.com/us/search/search-detail?id=op588






































When I put the IMEI into OP’s tool, it said I had to go through TMobile to [bootloader] unlock it since it was a retail model.
TMobile said the phone “wasn’t in our system” and couldn’t provide either SIM or bootloader unlock codes.