Hi,
It looks like you did not understand when I said there is a bug in Lottie that means you MUST have loop set to true or reverse will not work.
What you want to do is more complex than I worked out above but should be doable using the same principles.
I just had a look around trying to find a reference to if there was a get current frame in the Lottie API and found this thread which goes some way to point to what you want to do and validate what I worked out already.
I think my version and the info in that thread will hopefully help with this Lottie question.
There are probably other pointers out there. But ultimately I think you will need to get a handle on the API and some javascript. I do not think it will be that hard to finally figure out.
I hope this does not come across as condescending it certainly is not meant to and I am trying to show you how to find answers..
It can sometime seem hard in not knowing where to go but as an example on approach to problems like this.
Once I realised that reverse was not working, I search for Lottie reverse not working.
I found references that confirmed there was a bug and loop needed to be set to true.
But I did not find much more on how to fix this.
I now knew that loop had to be on which meant the animation would loop forever and the code would need a way to not only know when a loop completed but to stop the animation, reverse the play direction and start again.
So again I searched for reference on know when Lottie loop is complete, and so on..
My thinking walked along the path of what was needed of the animation and the logical steps to get around the road blocks to continue that path and then searching with the terms of the query as simple and direct as possible to what I currently want.