Answers for "- phpunit/phpunit[8.5.8, ..., 8.5.11] require php ^7.2 -> your php version (8.1.2) does not satisfy that requirement."

require php ^7.2.5 -> your php version (8.0.10) does not satisfy that requirement

composer install --ignore-platform-reqs

phpunit/phpunit[6.0.0, ..., 6.5.14] require php ^7.0 -> your php version (8.0.0) does not satisfy that requirement.

- phpunit/phpunit 5.5.4 requires php ^5.6 || ^7.0 -> your PHP version (7.0.26-2+ubuntu16.04.1+deb.sury.org+2) overridden by "config.platform.php" version (5.5) does not satisfy that requirement.