Is it just on initial start up ?
It’s hard to tell from the clip but it could be something as simple as being a bit “dry”. The oil drains to the sump and on start up it can sound a little rough. If the noise goes away after a few seconds and the oil level is ok I wouldn’t be to worried. My
Formentor 1.5 sounded a little rough on start up. Failing that check things like heat shield or any other ancillary bits, haven’t heard any issues with 1.5 engines rattling.