CRM On-Prem to D365 online migration (Mail Merge/Dialogs/Task Flows?)

Hello

I have a question related to CRM 2016 on-prem migration to D365 CE online planning and wondering if I can get some help for my below query.

What’s the equivalent replacement options out there for the below Three on-prem components that one should plan for ONLINE instance of D365:

1) Mail Merge
2) Dialogs
3) Task Flows

Thanks for your help in advance