Hi @Adil_Rana ! Welcome to the Community forum 
Happy to hear that you have been trying out our new app builder! Since it is in beta at the moment, there are features that are not available yet, but we are actively working on adding in the future.
We have added your +1 to public app sharing, and I recommend that you also follow this thread for any new updates on this feature for the new app builder!
-Jen