Whether you created the shoes yourself or downloaded them from another resource, you can "put them on" a Clo3D avatar. All we need to do is:
position the shoe around the foot,
adjust the shoe to the size and shape of the foot so it looks natural,
separate the left and right shoes into separate objects and name them correctly,
assign different materials to different parts of the shoe so we can edit them in Clo3D.
This can be done in Blender.
Please, if you have any questions and want a quick answer, ask them in the comments on the Telegram channel https://t.me/couture3d
or come learn how to work with real and digital clothing at https://3dcouture.ru/