Dane wrote:besides the normal contact form, is it possible to add one or more where you can add additional input fields? For example, questionnaires could be created for client requests, which they can fill out on their own.
The X3 contact form already accepts any form fields, so you can add your form elements however you like and they will get included in the email. You can find an example of an extended form here (scroll down to "Custom Forms"):
https://demo.photo.gallery/examples/features/sample/
Keep in mind, forms require basic knowledge of HTML so that you can add your form inputs. You can look at the existing basic contact form html code, and simply add/copy in your own elements. If you go to the content editor, you can also find an example of "advanced contact form", which you can use for reference.