How to filter ads & block popups on iPhone and in macOS?

Visit the settings page of AdGuard and enable these:

• AdBlocking: AdGuard Base & Mobile Filter
• Privacy: AdGuard Tracking Protection Filter
• Social Widgets: AdGuard Social Media Filter
• Annoyances: AdGuard Annoyances Filter, AdGuard Cookie Notices Filter, AdGuard Popups Filter, AdGuard Mobile App Banners Filter, AdGuard Other Annoyances Filter, AdGuard Widgets Filter, AdGuard Warning Removal List, Fanboy Annoyances Filter, Web Annoyances Ultralist, EasyList, Dandelion Sprout’s Annoyances List, I don't care about cookies (optional)
• Security: NoCoin Filter List & Online Malicious URL Blocklist
• Language: AdGuard Japanese Filter + [Your Country] Filter
• Other: AdGuard DNS Filter

These are my (minimum) toggles for the free version of AdGuard (which is enough) but make sure to enable both mobile and base filters regardless of your device type, which I try to mirror on both macOS and iOS. You may have the luxury of more filters if you're on the newer version but it's not necessary to enable every single filter like for Language List outside of the languages that are part of your multilingual life.

Despite these, if you still end up with any form of ads leftover then head to Support → Report Incorrect Blocking after confirming your filters are updated or the extensions are active and the people at AdGuard would take a max of three days (they're very active) but rarely over 7 days to address them.

Note:

• Don’t forget to check Safari Settings as well and give it a restart when your filters are updated.
• If you have been unable to load the video player due to backend changes then reinstall AdGuard and restart Safari, after updating the filters you’re good to go.
• If you're having difficulty accessing the site (or facing buffers) then use CloudFlare Warp (VPN) with a Gateway DOH Subdomain that whitelists vid2a41.site (Advanced → Connection Options → DNS Settings)

• If you have just enabled the rules then update the filters first and wait for it to finish.

Test if you’ve managed to activate the filters:

• https://adguard.com/en/test.html
• https://adblock-tester.com
• https://canyoublockit.com/extreme-test/