require.Some/Package is invalid, it should not contain uppercase characters.Please use some/package instead.Issue
Composer 2 is more strict than Composer 1. One of the areas are package names should use lowercase names, regardless of casing for the repository name.
Solution
While this is a warning and not an actual error, you should still resolve this by using the proper lowercase name of the package in your composer.json requirements. If the package truly contains uppercase characters in their composer.json, you should notify the package author of this message by opening an issue or a pull request.