Trigger on demand Lambda

[ysennoun]

Hello,

I am building an application where I need to add a button in the WorkMail interface that enables a user when he presses on it to transfer files received in a mail to a s3 bucket. I know there is example where the mail is received the lambda automatically is triggered to do the process. Now, I want to do it on-demand with an add-on button in the WorkMail interface in order to trigger it. Outlook and Gmail provides extensions to do that. Is it possible to do something similar ? if no, what are the alternatives for me ?

Thank you,
Regard.