Just Update this requirement to php: “^7.3|^8.0” something like this.
"require": {
"php": "^7.3|^8.0",
},"require": {
"php": ">=7.3",
},paragonie/random_compat v9.99.99 requires php ^7 -> your PHP version (8.1.5) does not satisfy that requirement.
in Ubuntu
