That website
https://cryptocurrencyalerting.com/bitcoin-mempool.htmlprovides notifications via email, Telegram, Discord ... for mempool but it is not much useful. Because the option is for mempool size (total).
I think it would be more useful if notification is for lowest fee rate in sat/vbyte for 1 or 4 MB from tip of mempool.
A second site is
https://txfees.watch/It has a feature I discussed but only provides notification via email.
I think it will require a little bit modifications. Anyone can build it?
Just my 2 sats idea for community as I knew some members built Telegram noification bots for other things.