Was the 1815 Tambora eruption a Convergent Plate Motion, a Divergent Plate motion, or hot spot activity?

i know mount Tambora in Indonesia was on a convergent plate boundary. Does that mean that the 1815 major eruption was the result of a convergent plate motion or was it a divergent plate motion or hot spot activity that caused it. please answer quick! and please leave resources! thank youu!