Tutorials

Fuse was model making software that worked on a Mac... if you ask around then it quickly becomes known that 3D is a Windows users only club which is really why Adobe wanted the staff from Fuse

since then Apple Mac has dropped 32bit and just come out with M1... both of which have flipped the table on companies which make software for Mac systems so we can expect a long catch up period now

Mixamo is a dirt simple tool to rig human shaped models for their bones, it was made to use with Fuse characters and once had the extra option to add face blends so you could have your model smile or roll her eyes but that only worked with Fuse and is gone now... you can still rig a basic human shaped model (from some 3rd party software or vendor) but you need a machinima like Unity, Unreal or Iclone to play the downloaded animations or a simple 3D editor like Photoshop, Blender and C4D to stitch them together one at a time into a gif or movie file

There are plenty of tutorials for Mixamo, but many of them rely on a third party 3D software to build the character, or to incorporate the captured data to your scene.

The first thing I'd ask (now that Fuse is not available through CreativeCloud), is what are you using for your 3D pipeline?

(and a better question might be, "what do you want to do with the mixamo data"?)

if you uninstalled Fuse without making a backup you are indeed screwed... in fact if you believed the BS Adobe told you and allowed creative cloud to auto update then you are also screwed

you can still export a Fuse character (assuming you still have it working) and upload that model to Mixamo yes but the model you end up with will not have face blends (bones to move the eyes or smile for example) and is also different to the UV that we used to get from uploading Fuse models dirrectly to Mixamo from Fuse before Adobe killed it

there are old tutorials for Fuse and Mixamo but most of them are worthless now because the background code has been changed