Oneplus 7t pro isn't detected by the easy installer

[mihi]

Hmm since you are allready on android 12 stock, you don’t need to update vendor firmware anymore, as it is explained here at Lineage:
https://wiki.lineageos.org/devices/hotdog/fw_update

I would say you can do as anon29344687 did and extract recovery and install it with fastboot

@anon29344687

First I unzipped e-1.15-t-20230917331436-dev-hotdog.zip, then unzipped the payload.bin file it contained, which in turn contained recovery.img (v.1.15) among other things. The next step was the installation of e-Recovery (v 1.15) via fastboot. Afterwards the successful installation of e-1.15-t-20230917331436-dev-hotdog.zip via adb sideload.