Could not resolve all files for configuration ':runtimeClasspathCopy'.
> Could not find net.minecraftforge:forge:1.16.5-36.2.34_mapped_official_1.16.5.
  Searched in the following locations:
    - file:/C:/Users/alexa/.gradle/caches/forge_gradle/bundeled_repo/net/minecraftforge/forge/1.16.5-36.2.34_mapped_official_1.16.5/forge-1.16.5-36.2.34_mapped_official_1.16.5.pom
    - file:/C:/Users/alexa/.gradle/caches/forge_gradle/bundeled_repo/net/minecraftforge/forge/1.16.5-36.2.34_mapped_official_1.16.5/forge-1.16.5-36.2.34_mapped_official_1.16.5.jar
  Required by:
      project :

Possible solution:
 - Declare repository providing the artifact, see the documentation at https://docs.gradle.org/current/userguide/declaring_repositories.html

i already tried deleting forge_gradle, but didnt work

The version you are using is no longer supported on this forum.

Please update to a modern version of Minecraft to receive support.

Currently supported versions are 1.19.2 (Latest) and 1.18.2 (LTS).