Hello FFEMTP22,
To clarify, do you have more than one email account set up in the Mail app? If so, does this issue occur for a specific account?
We ask this because, depending on the type of email account you have, you might see Archive instead of Trash when you try to delete emails. However, you should be able to edit where your deleted messages go in your Mail settings. Here's how:
"Set Trash or Archive as your default option
- In the Settings app, tap Mail.
- Tap Accounts.
- Tap your account.
- Tap your account once more.
- Tap Advanced.
- Select Deleted Mailbox or Archive Mailbox to send discarded messages there.
Swipe to delete and other ways to discard one email
- Swipe left quickly over a single email.
- Touch and hold an email from your Inbox, then tap Trash Message from the menu.
- Tap the Archive button
or the Trash button
from within an email.
You can also use the steps to delete multiple emails to delete a single email."
More details here: Delete emails on your iPhone or iPad
Let us know if this helps.
Cheers.