Docker issue "requested access to the resource is denied"

Question

PS C:\Users\user\Desktop> docker login
Authenticating with existing credentials...
Login Succeeded
PS C:\Users\user\Desktop> docker push tree
The push refers to repository [docker.io/library/tree]
701ae319ce59: Preparing                                                                                                                
1445d87cb5ce: Preparing                                                                                                                
a9e822192dd4: Preparing                                                                                                                    
91ad130083b0: Preparing                                                                                                                        
096da3f810e4: Preparing                                                                                                                
508c3f3b7a64: Waiting                                                                                                                  
7e453511681f: Waiting                                                                                                                  
b544d7bb9107: Waiting                                                                                                                  
baf481fca4b7: Waiting                                                                                                                  
3d3e92e98337: Waiting                                                                                                                  
8967306e673e: Waiting                                                                                                                  
9794a3b3ed45: Waiting                                                                                                                  
5f77a51ade6a: Waiting                                                                                                                  
e40d297cf5f8: Waiting                                                                                                                  
denied: requested access to the resource is denied

Answer 1

That is because you don't have push access to the docker.io/library/tree repository. If you want to push an imge you created, to docker, you have to do it in your account, i.e. the push will be like

docker push <your-username>/tree