I have tried to follow Fernanda's instruction to embed a Hot Pot exercise in Motime blog and succeeded for the first time, but then it was unable to manage with the different exercises. Take a look at my Motime blog.
The second advice is the best:
"Anyway, I would say this is not practical. The best way is to get a server and upload your files there.You can also upload your file and then create a link to it, instead of embedding it in the blog: Write - add file -upload. Then select the file and the blog will create a link to it.Tell me if you succeeded! Beijinhos, Fernanda."
Thank you both, Nelba and Fernanda.