Q:

Flow only Available for Modern Experience

I used to have one Document Library in classic Experience ánd Flow was not available. (that's why I thought it was not included in our purchase )
I know created a new Document Library on the same SharePoint and Flow is avaiable and I can create flows.
Anyone know why its not there for the classic Experience.

A:

You can use Flow with classic, you just can't do it from the command bar. You can go into Flow directly and work with your classic sites/libraries from there.

A:

It's by design that Classic lists/libraries do not have option of flows internally. You need to change it to modern experience. Starting a flow from Flow Launch Panel is is only available on all modern SharePoint lists and libraries currently.
Here are some similar post:
https://powerusers.microsoft.com/t5/Building-Flows/Manually-Run-a-Flow-using-Classic-Experience/td-p/96998
How to start a microsoft flow in SPO Classic Experience?

