Hello Graciano,
It looks like you have 2 email accounts registered (one with @gmail.com and the other with @ono.com ). 

• Go to: https://rntlab.com/account/
• While you are logged in… Which email address do you see there? 

You should be logged in with your gmail account. Then, if you go to the https://rntlab.com/courses/ link you should be able to download your eBooks.

Hello. I access with gmail account.

What happens when you try to open this link while logged in?

• https://rntlab.com/module-1/learn-esp32-welcome/

Solved. Thanks

I’m glad it’s working now. If you need further assistance just let me know!
Regards,
Rui