Your requirements could not be resolved to an installable set of packages.
Problem 1
- Root composer.json requires lcinhk/flarum-ext-acgembed ^0.5.2 -> satisfiable by lcinhk/flarum-ext-acgembed[v0.5.2].
- lcinhk/flarum-ext-acgembed v0.5.2 requires flarum/core ^0.1.0-beta.8 -> found flarum/core[v0.1.0-beta.8, ..., v0.1.0-beta.16] but it does not match your minimum-stability.
Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.
You can also try re-running composer require with an explicit version constraint, e.g. "composer require lcinhk/flarum-ext-acgembed:*" to figure out if any version is installable, or "composer require lcinhk/flarum-ext-acgembed:^2.1" if you know which you need.
Installation failed, reverting ./composer.json and ./composer.lock to their original content.
