Taken from CE Integration: https://docs.particle.io/guide/how-to-build-a-product/certification/#integration-2
“Manufacturers who place on the market products without an antenna or with an antenna that is intended to allow replacement have a responsibility to provide information on the general types and/or characteristics of antennas that may be used with their equipment in order that the overall radio equipment remains compliant. The guidance of the transmitter manufacturer has to be followed when they are installed.”
For the Photon/P0 and P1 Modules, these integration instructions are the same as for the FCC/IC–so long as you’re integrating the modules without modifying the RF design or implementing an antenna with gain greater than that used in certification, your equipment will likely remain compliant.
The Photon/P0 and P1 Modules are certified with ETSI radio tests which can be accepted by a number of countries for radio compliance.
It sounds like if you are using a Photon but not modifying the antenna you are fine.