Beginner here wanting to use a pre-trained model, confused trying to do simple things

So I found a pre-trained model that greatly interested me:
https://github.com/OMR-Research/tf-end-to-end

Probably irrelevant but I found it from this article and maybe
you’d like to read it too:
https://heartbeat.fritz.ai/play-sheet-music-with-python-opencv-and-an-optical-music-recognition-model-a55a3bea8fe

I wanted to play around with it in the context of an android
phone and I found out that tensorflow can support this easily if I
can just convert it into TFLite format. Problem is, I’ve been
having so much trouble getting the model into it, but it’s likely
my lack of experience in dealing with such a complex model.

This is the model I’ve been tooling with https://grfia.dlsi.ua.es/primus/models/PrIMuS/Semantic-Model.zip

So in order to get it into TFLite format, I needed to get its
.meta / .index / .data files into a frozen graph, however, to do
this you would need to know the input and output nodes which I had
trouble understanding, even with tensorboard summaries. Another
method I found was through the savedmodel format, however I was
getting all sorts of errors detailed in my stack overflow post that
you can maybe help with:
https://stackoverflow.com/questions/65572476/how-do-i-convert-a-meta-index-and-data-file-into-savedmodel-pb-format-with

So basically, I just want to convert my checkpoint file into a
usable file for inference and getting really lost and need some
advice.