However, if you have a specific setup where Termux can access fastboot interfaces (rare and requires root/custom kernel), the command would be:
Here is everything you need to know about the "unlock bootloader using termux link" method. What is the "Termux Link" Method? unlock bootloader using termux link
However, (e.g., engineering bootloader, unlocked aboot, or using an exploit like CVE-2020-0041). However, if you have a specific setup where
Unlock Bootloader of any Device using PC or Android. - GitHub unlock bootloader using termux link
This is the legitimate method to unlock from your phone using another phone as the "PC".