Macedonians are not Bulgarians. Bulgarians are not even Slavs. The languages are similar but not the same. I’m fluent in Macedonian but I need an interpreter for Bulgarian.
All Slavic languages are similar. For instance I don’t speak Slovene, Czech, Slovak, Russian but I can understand those languages to some extent in written form, especially Slovene.
The only Bulgarians in Macedonia are Macedonians who obtained
Bulgarian passports to work in European Union.
During Macedonian struggle for self determination in 19th and early 20th century there were factions on a payroll of Bulgaria, Serbia who fought to divide Macedonian population and get them on their side.