@robinsing, I've been followed this topic in order to completed the installation but i changed at starring the 9th of another computer where ubuntu and ubports was installed and follow these instructions to allowed and enabled the fastboot and unlock bootloader.

@rheomie , i'm a french user of this forum and i'm not sure my english words will be correct.
I followed your instructions with a windows 11 computer; but at the 9th, I had pluged the device on another computer where ubuntu is installed.
I had installed ubports installer with a snap app.
The installation had been completed at a second try with the snap app cause the first attempt not respond, so i had relauched the ubports installed and then the installation has been finished and completed.

@Moem thank you for your reply.
I will wait about news.

Hi everyones,
I've just finished of flashing my "new" nexus 7 LTE and i write this message with it.
I'd like to know if this phablet will be supported on Focal (OTA-4)?
It runs actualy with the Xenial (OTA-25).