How to spoof/change IMEI that is sent to the service provider using an open source or "official" software?

I bought my phone (Pixel 2 XL) abroad and hence, my IMEI is not present my country's IMEI registry. Hence, I'm not allowed to use any service providers. Hence, I want to spoof/change my IMEI so that the service provider will receive a different IMEI and hence, I will be able to use my phone. What's the most secure way of doing this? I believe there used to be the PDroid project but AFAICT, it is not maintained anymore. Likewise, there's the [Xposed framework](https://github.com/rovo89/Xposed) , but it doesn't seem to be maintained either. I guess I can also use stuff like Qualcomm Product Support Tool (QPST) to change the IMEI directly on the chipset, but I wasn't able to find an "official" copy. That is, I registered to Qualcomm's website but they don't let me access to their "support software" section. Hence, I cannot download an "official copy" of QPST. So, what are my options here? I would prefer to use an open source software, or if closed source, prefer the software to be directly provided by an "official" source, such as Qualcomm, etc.