“Panels” tab missing in Post preferences

Hi everybody, I searched in the forum but didn’t find any answer, I would like to access to the “Panels” options to activate the additionnal “Custom field” for post, but there is no “Panels” option in the preferences window. I can see: General / Appearance / accessibility / Blocks, but not the Panels.
The doc I was folowwing: https://css-tricks.com/use-custom-fields-in-wordpress/

Do you have any idea of why this option doesn’t show off and how to fix that?
I have the Hello Elementor theme activated.
Thank you for your help!