What category should I choose for "Interest Charge Purchases" on my credit account?

Good day, 32SNT23.

The Interest Charge Purchases is considered an interest in a Schedule C categorization. However, I'd still recommend reaching out to your accountant as to what specific interest it belongs.

I've added this link for more information about Schedule C categorization: Schedule C and expense categories in QuickBooks Self-Employed.

Keep me posted whenever you have other concerns. I'll be around!