Do you have any way to root lem12? I tried via magisk but it does not see my boot.img file.
rename it to boot.png and it will see it
Did not work. But I noticed that on the left side there should be a tab where you can choose the save location. On this screen you can not see but how I installed it on the phone it is.
ok, some other workarounds you can try are:
upload it to google drive and then download it to your watch from there
install this apk as an update (it will be overwritten by the stock one on next boot):