Install bitcoin core from https://bitcoin.org/en/bitcoin-core/ and then use the walletnotify setting to have it call a custom script any time you receive a transaction. Your script can call other API's or programs that notify you or take some automated action.

Here's some info on using walletnotify: https://bitcoin.stackexchange.com/a/24483/31974

Adding nostr support to https://coinos.io

I've been livestreaming my progress on my twitch channel: https://twitch.tv/asoltys83