Configure MX records on Namecheap in order to use the domain with OVHCloud email

Hi,
Noob at setting up an email service, sorry if my question is a bit stupid.

I've been looking at many threads but can't find an answer to my problem: I have a domain registered through Namecheap, but I would like to use OVH's email services. This requires me to set up different things on Namecheap: MX, SRV, SPF and DKIM.
DKIM: I did it!
But despite my efforts, the 3 others don't work. Yet, I diligently followed the steps explained in the guides, tried different solutions, and waited 24 to 48h for the records to propagate each time.

Although the email seems to work (I could send and receive messages), I trully need to have all the buttons turn green (see picture attached) for I can't fully understand the effects of it not working and I'm building the email service for a beautiful non-profit that I'm trying to help.

I'm mainly focused on MX records, for a start. I tried to set up an A record in order to make it work but found myself with another problem: OVH doesn't provide me with an IP address.
See below screenshots of what I see, and if you have any idea to make the MX record registration work, that would be a huge help!

Other infos:
- I'm doing that from France (Paris)
- I can't buy a slightly different domain on OVH to simplify it all, for its name has been decided collectively
- I can't transfer the domain to OVH at the moment because it has been created less than 60 days ago
- they needed the email address 2 weeks ago...!

20|690x469!
59|690x224

THANK YOU !!!!