How to get access to adobe workfront fusion for practice

Talk to whoever owns your partner sandbox. There is no Fusion "testdrive"

You can also signup e.g. for Make.com which still has large overlap with Fusion but is missing Adobe-specific modules. 

I agree with @sven-ix 

make.com is a great way to work with the modules a understand how they work.   Not very Adobe specific but gives you a good playground to work with.

We have also attached our Fusion to the Preview environment to try out Scenarios that we are not really sure what we are going to get, then change the Connection to the Production environment.

@kumarisu just checking in! Were you able to get this resolved? If one of the replies above helped—whether it completely solved the issue or simply pointed you in the right direction—marking it as accepted can make it much easier for others with the same question to find a solution. And if you found a different way to fix it, sharing your approach would be a great contribution to the community. Your follow-up not only helps close the loop but also ensures others benefit from your experience. Thanks so much for being part of the conversation!