I want to use my own content. I assume this is possible.
Yes, the program has a flexible choice of exercise materials. This will empower teachers to individualize instruction and allows them to either use the typing exercises provided or easily import their own material from virtually any file format including PDF, DOCX, HTML, or any URL.
Best Regards,
Aidan Bernales
Community Moderator at Typesy
Hello, @salimmayo!
Typesy is super customizable - you can absolutely add in your own text or lessons for students to use.
I really like using the typing games to have students practice weekly spelling words. Helps them both with typing and spelling, and I hear a lot less complaints when it comes to studying our spelling words!
It has been a few months since you posted - were you able to get started? Whether for yourself or for students, now is a pretty good time for programs like Typesy! Plenty of indoor time 
Regards,
Alex (The Reimagined Classroom Teacher)