Answers for "problem 1 - root composer.json requires php ^7.2.5 but your php version (8.1.2) does not satisfy that requirement."

Root composer.json requires php ^7.2.5 but your php version (8.0.6) does not satisfy that requirement.

composer install --ignore-platform-reqs

- root composer.json requires php ^7.1.3 but your php version (8.0.3) does not satisfy that requirement.

It's becouse in your project in composer.json file you have:

"require": {
    "php": ">=7.3",
    .....
},
Try to update this requirement to:

"require": {
    "php": "^7.3|^8.0",
    .....
},

- root composer.json requires php ^7.2 but your php version (8.0.1) does not satisfy that requirement.

Your project using php7.2 version and composer installed with 8.0.1.
Update your composer with php 7.2 instead 8.0.1. problem will solve.