⚠️Current Java is 17 but we require at least 21

This error may not be exactly the same, but the fix to this is to change your java version to the java version which the error requires you to use. For an example, in this error:

Exception in thread "main" java.lang.IllegalStateException: Current Java is 17 but we require at least 21

It states that we are using Java 17 but the version of Minecraft we have installed requires Java 21.

To change the java version, head over Settings and change the Java Version Varible to the correct java version.