Hi @Kruthika,
Based on the issue that you mentioned, do you want to download the attachments from the SP list?
Could you please share a bit more about the scenario?
If you want to download multiple attachments at a time within the Gallery, I am afraid that there is no way to achieve this within PowerApps currently.
If you would like this feature to be added in PowerApps, please submit an idea to PowerApps Ideas Forum:
https://powerusers.microsoft.com/t5/PowerApps-Ideas/idb-p/PowerAppsIdeas
As an alternative solution, I think you could download the attachments one by one.
1. add an file icon in the gallery
2. set it Visible property:
ThisItem.'Has attachments'
3. set it OnSelect property:
Launch(First(ThisItem.Attachments).AbsoluteUri)
Note that if you have multiple attachments, you should modify your formula as you want.
Regards,
Qi