According to rule 9 it is at least Class IIa. Considering the substantial risk when putting a microwave heated device on the eye I believe Class IIb may be justified! This depends on risk assessment. How is the temperature controlled?
Class IIa is already applicable under MDD, rule 9 (active therapeutic device intended to administer or exchange energy)

Thanks, Gottfried for your response.

There is no control over the temperature but suggested to keep for while inside the micro oven to absorb heat.
https://www.youtube.com/watch?v=gBgqZsdCYAw

There is no indication of a CE-mark! Without CE-mark it must not be distributed in Europe via Amazon!

Yes its not visible but this is CE marked. I have checked their website and got this claim- "All of The Body Doctor products are tested voluntarily to BS8433/2004 Personal Warmer test. CE certified. Our products have also passed: REACH BSEN 14362-1/2, Pesticides, EN71 Pt 3."

https://www.the-body-doctor.com/professional-resources/

If it is CE-marked, there must be the CE symbol on the product (not smaller than 5 mm) together with the 4-digit registration number of their notified body, who issued their EC-certificate.

i guess guideline says , this minimum dimension may be waived for small-scale devices.