just so you know terrorism is illegal in basically every non-anarchist or "free-world" (most of the time third world) country on earth.
judging by the language you're speaking,
https://tips.fbi.gov/home 🇺🇸
https://www.gov.uk/report-terrorism 🇨🇦 https://www.canada.ca/en/security-intelligence-service/corporate/reporting-national-security-information.html 🇨🇦
https://www.nationalsecurity.gov.au/what-can-i-do/report-suspicious-behaviour 🇦🇺