Well, it’s really up to you and how you feel about it when you see it. You really should only surround yourself with things that have a positive effect on you.
If you’re writing in about it, perhaps you feel a little nudge that this should not be in your possession. If that’s the case, be open to signs for how to deliver it to the appropriate person or establishment.
When you open yourself up to this, perhaps you meet someone who has a connection to it, or you see a museum, school, or library highlighting Indigenous history. If this falls into place, go with it.
If you feel like it’s something you need to respectfully pass on, then make that effort. You can check with a nearby tribe, library, or museum to see if there would be an appropriate holder.
Indigenous people are animist and believe that inanimate objects hold energy and power. I might say a prayer that releases any harm or negative energy the flag may have caused and the pledge to do your part in uplifting your Indigenous neighbors.
I thank you for writing in and I’m proud of you for being such a great ally.