I fixed my BTCPay server issue. For anyone that runs Umbrel and has the same issue, it's an easy fix. The issue is a result of Umbrel's version of BTCPay server being old.

ssh to your node.

sudo /home/umbrel/umbrel/scripts/app stop btcpay-server

cd /home/umbrel/umbrel/app-data/btcpay-server/

sudo vim docker-compose.yml

look for the nbxplorer line at the top.

change the image being currently used to the latest version like this.

nbxplorer:

image: nicolasdorier/nbxplorer:2.3.58

sudo /home/umbrel/umbrel/scripts/app start btcpay-server

All fixed!