Want to ask a colleague to contribute to your slide deck, and want to point them directly to the slide you need help with? In PowerPoint for the web just right-click the slide you want assistance with and choose Link to this Slide.
When the sharing card appears you can change the share settings - if you only want your colleague to view the slide, and not edit it, for example - or just click Copy to copy the hyperlink to your clipboard.
Once you have it copied to the clipboard you can paste it into an email message, Teams chat, or whatever method you want to share it with your colleague.
Note: The person you share the link with can access your entire slide deck; they'll just be taken to the slide you selected at the start.
Here's a quick video of Link to this Slide in action.