Hello SarahGunn-0093, Microsoft Teams does not currently provide a built-in feature for read receipts on posts made within channels or chats. This includes posts made through tabs, bots, or message extensions.
Thank you for your suggestion! To better achieve your requirements, we recommend submitting this feature request through the Teams Feedback Portal. This is the best way to ensure your idea is considered for future updates.
We appreciate your input and encourage you to share any additional thoughts!