Sincere apologies for the delay in responding @Aleksandra
You should be able to get your app ID by going to Log in - Asana and expanding the details of your app. It is labeled “Client ID.”
If this doesn’t help, I would highly recommend you to contact our Support Team following these steps. They will be better equipped to assist you with this issue.
I hope this helps Aleksandra! Apologies for not being able to assist you via Forum but we don’t have the proper tools to do! I hope you are safe and taking care of you and yours during these difficult times.