Cannot make an internal link to a header/index

browser: firefox
COOLWSD version: 24.04.11.1(git hash: 8d0ad9add2 (E))
LOKit version: Collabora Office 24.04.11.1(git hash: 91fe8fb)
Served by: Debian GNU/Linux 12 (bookworm)
Server ID: d4cc52d5
WOPI host: nextcloud 30.0.2.2 - richdocuments 8.5.3

Hello, I want to insert a link back to index before each page break. I tried copying the link the index itself has #__RefHeading___Toc625_1065506798 but when I insert it into a hyperlink it adds http:// that I cannot remove and makes it invalid. I see here “bookmarks are converted to anchors that you can jump to from a hyperlink.” but I cannot find a way to copy its address. I also see here that I should be able to drag from navigator but the links aren’t draggable and only take you to locations upon double click. I see there should be a drag mode button, but I do not see that anywhere. Please advise, thank you.