I see the signal at x3 the desired frequency. (Aliasing?)

Dear All,
My signal of Interest is around 70 MHz @ -50 dBm. When I inject a signal around 210 MHz @ -50 dbm the signal at 210 MHz becomes prevalent. Is there a mixer setting to prevent aliasing?
Thanks in advance.

The simplest option is to add an external LPF Low Pass Filter (or Band Pass Filter) with a cutoff at a frequency anywhere above 70 MHz.
Either buy one or build one

Or see other suggestions in the linked thread, the last post in that thread has some really good information.