Pagging
You can either use the alt text of the image for pagging or use an attribute
page for pagging if you have the attr_list markdown extension installed in
your mkdocs.yaml.
markdown_extensions:
- attr_list
Examples
Below you should see diagram Page-1:

Below you should see diagram Page-2:

Below you should see the diagram Page-2 using the page attribute:
{ page="Page-2" }
If the alt text doesn't exist as a page it will fallback to the first page of your diagram. Below you should therefore see Page-1 (default):
Furthoremore, you should see a warning in your mkdocs server similar to:
WARNING - Warning: Found 0 results for page name 'Page-3' for diagram 'test.drawio' on path '/tmp/mkdocs_ce1qjhyn/test2'

If the alt text and page attribute don't exist as a page, it will fallback to the first page of your diagram. Below you should therefore see Page-1 (default):
Furthoremore, you should see a warning in your mkdocs server similar to:
WARNING - Warning: Found 0 results for page name 'Page-3' for diagram 'test.drawio' on path '/tmp/mkdocs_ce1qjhyn/test2'
{ page="Page-3" }
Pagging logic for SVG diagrams is skip as only a single page can be exported as an SVG drawio diagram.
{ page="Page-3" }