I found a compatible one on Amazon: https://www.amazon.com/dp/B08N62RM1N. This is Delta BSB05505HP-SM.
I would point out, however, that this noise may be the result of the thermal paste under the heatsink starting to dry out and the fan is running faster than normal to compensate. If you want to attempt to replace this paste, be very careful as there is also a thermal foam pad attached to the heatsink and it can easily be damaged (I use an exacto knife blade to ensure that the pad peels off the heatsink without being torn or stretched).
Hope this helps,
...S
