If the bootloader is unlocked, you can look up miunlock tool or just use adb sideload to flash a custom rom like Crdroid or lineage os. Miunlock tool allows you to flash the stock rom, which means all of your data will be lost. If the bootloader is locked, you only option would be to get the phone in edl mode. This would also allow you to flash the stock rom. You would need an edl cable for this. Here is a guide on how to use the edl method https://www.reddit.com/r/PocoPhones/comments/1kqm2bk/guide_how_i_unbricked_my_bricked_poco_f3_alioth .. I advice you try other methods first since this method would erase all your data.