Your logbook must contain enough information to determine whether you meet the relevant recency requirements of your certificate.
The wording of this is not super clear in EASA regulations. From FCL.060:
A pilot shall not operate an aircraft
in commercial air transport or carrying passengers [...] as PIC or co-pilot unless he/she has carried out, in the preceding 90 days, at least 3 take-
offs, approaches and landings in an aircraft of the same type or class or an FFS representing
that type or class. The 3 take-offs and landings shall be performed in either multi-pilot or
single-pilot operations, depending on the privileges held by the pilot.
Which leaves open the question of what counts as "carrying out" a takeoff, approach, and landing. From the night recency requirements in the following paragraph (emphasis mine):
[A pilot shall not operate] as PIC at night unless he/she [...] has carried out in the preceding 90 days at least 1 take-off, approach and landing
at night as a pilot flying in an aircraft of the same type or class or an FFS
representing that type or class
Night recency specifies "pilot flying." By implication "carrying out" does not imply that you are the pilot flying, and so the pilot monitoring can log the takeoffs, approaches, and landings towards their recency requirements.
Note that this is a deviation from ICAO. The relevant ICAO documentation is crystal clear that you must be the pilot flying for it to count. From Annex 6, Part I, Section 9.4.1.1:
The operator shall not assign a pilot-in-command or a co-pilot to operate at the flight controls of a type or
variant of a type of aeroplane during take-off and landing unless that pilot has operated the flight controls during at least three
take-offs and landings within the preceding 90 days on the same type of aeroplane or in a flight simulator approved for the
purpose.
It would be a good idea to log PF and PM landings separately, since if you fly outside of EASA airspace you may be beholden to the more restrictive currency requirements of the relevant country. You need to distinguish between PF and PM for night recency anyway.