How to allow & in text input

[FaizPrasla]

The '&' character after sanitization gets converted to & is there a way to allow & character without it being sanitized. Would something like sanitizer.AllowedSchemes.Add("&") work?

[mganss]

No, this won't work. AllowedSchemes specifies the allowed URI schemes, like http, ftp, mailto etc.
The ampersand character & is reserved in HTML, see https://developer.mozilla.org/en-US/docs/Glossary/Entity
The parser in AngleSharp "corrects" some malformed HTML by converting spurious characters into its equivalent entities, making the resulting HTML more valid. See also the section here: https://github.com/mganss/HtmlSanitizer#text-content-not-necessarily-preserved-as-is

[mganss]

If the text is not displayed as HTML, i.e. not in a browser where XSS can occur, then sanitizing shouldn't be necessary at all.

[FaizPrasla]

Text field is in a web app. So its browser submit button.

[mganss]

Where will the text be displayed again after it has been submitted?

[FaizPrasla]

Same browser in some component on the same page as where you open a modal to submit text.

[mganss]

But it's also displayed elsewhere in a non-HTML environment? Perhaps it's best to keep the original unsanitized input alongside the sanitized HTML. This way you can display the sanitized HTML in the browser and still have the original input for display in the non-HTML environment.