Do Profile Backlinks Work for SEO? Not Showing in Ahrefs/SEMrush

As a beginner in SEO, I've been trying to build some authority for my site by creating profile backlinks through social media profiles and forum profiles. However, when I check these backlinks in tools like Ahrefs and SEMrush, I can't seem to find them listed. Do profile backlinks actually work for building authority? And if they do, why aren't they showing up in these SEO tools? I want to make sure I'm not wasting my time on ineffective link building strategies. Thx