You have to update your package composer so he will fit with the new require.
Deprecation warning: Your package name PHPRecipeBook is invalid, it should have a vendor name, a forward slash, and a package name. The vendor and package name can be words separated by -, . or . The complete name should match "[a-z0-9]([.-]?[a-z0-9]+)/a-z0-9". Make sure you fix this as Composer 2.0 will error.
You have to update your package composer so he will fit with the new require.