Uncaught Security Error: Block a frame... when read online on Safari and Chrome

Hi everyone, this is my first post on this forum.
I hosted my server on my old windows PC for few months and now for some reason I took a next step and try to learn and host calibre on ubuntu on a cloud.
Everything goes as planned but for some reasons when I use chrome and safari to open online any book this error pop up. I tried with Brave and nothing happen.

I follow exactly this tutorial on create service and config apache2

https://www.digitalocean.com/communi...n-ubuntu-20-04

I don't know what else to provide but i can provide more information
thank you very much

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