Can’t change widget content

Hello @michelfolk

I hope you are doing well

I understand your concern and you want to change sidebar widgets then you can refer to this article https://visualmodo.com/knowledgebase/adding-sidebar-wordpress/
or you need to remove the sidebar widgets then you can use this CSS to hide the sidebar widgets.

How to apply CSS in WordPress Admin Dashboard :
1. log in to your WordPress Admin Dashboard
2. Appearance > Customize > Additional CSS
3. paste this code over there. and you good to go

/*CSS to Hide Sidebar*/
#primary-widget-area {
display: none;
}

or you face any issue regarding WordPress replies from this POST. I would feel happy to help you.

Can you send me a screenshot of your dashboard and plugins maybe you have added a plugin that occurs problem.

https://ibb.co/mcBXHDV

here is the screenshot of your website I hope you will get the plugin that is using in this sidebar.