Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires php ^8.1 but your php version (8.0.30) does not satisfy that requirement. Problem 2 - Root composer.json requires nexusphp/tachycardia ^2.0 -> satisfiable by nexusphp/tachycardia[v2.0.0, ..., 2.x-dev]. - nexusphp/tachycardia[v2.0.0, ..., 2.x-dev] require php ^8.1 -> your php version (8.0.30) does not satisfy that requirement.