Link to bookmark with space in Bookmark

I have a PDF document that is going to grow as time goes on and will be accessed from a Web Browser. I have Bookmarks created from topic headings and I can link to the correct page using the format:

<a href="https://requestedPDF.pdf#Bookmark1">

The problem is that many of the bookmarks have a space in them and don't work in a hyperlink. I have tried:

<a href="https://requestedPDF.pdf#Bookmark 1">

and

<a href="https://requestedPDF.pdf#Bookmark%201">

But that doesn't work besause I think that special characters and spaces are not allowed in the PDF open code?

Destinations don't work like I need because as the document grows, the destination will not be on the correct page.

Creating Bookmarks without spaces doesn't look correct either.

What is the method to link to a bookmark that has a space in the bookmark or another method to achieve the dynamic location for a link?