I was thinking Excalibur Red Lime Hybrid.
https://citrusvariety.ucr.edu/citrus/excalibur.htmlOther 'Red Limes" seem to have more pointy leaves than Rangpur.
Some Limequats have pointy leaves, but the fruit colour is wrong for most of those.
Other helpful to ID a Citrus would be where it came from.
Is it a grafted tree from a nursery, that would tend to narrow it down to known types.
Is it a seedling in someones yard, that could widen the possibilities.