I think it’s ok to keep using the term Indian because many within the Native American community have indicated a preference for it.

Also “Native American” is a kind of sterile word made up in the 1970s by coastal libs and so some within the Native American community feel it’s too clinical and empty of meaning.

It’s true that Indian is colonial and hilariously inaccurate but it’s been used for centuries and so becomes imbued with meaning and identity through so much use.

Ideally you use the specific tribal name since they aren’t a single people, like it’s a false category since it isn’t a singular identity anyway except for being defined in contrast to non-indigenous Americans. So where possible avoid the collective noun anyway but when the collective noun is required then the general consensus within the Native American community is that either “Indian” or “Native American” is acceptable, with some taking strong exception to “Indian” due to it being inaccurate but also many equally taking exception to “Native American” for being clinically dehumanizing and equally imposed by white colonizers.

I think the best is to defer to the preference of current company but the idea that the term “Indian” at least has been imbued with a strong cultural identity makes sense to me.