I assume you are talking about GPS data from your drone. The thermal template is optimized for thermal images. This pipeline uses alternative calibration mode which gives some weight to the geolocation data which is why that template needs GPS data. You can process thermal images with standard calibration though it might not give you the best results. So start your project, you will not be able to select thermal template if you don’t have GPS data. Select any other template (like 3D maps). Then select the thermal template (you will be able to select it now) and change the calibration mode to standard. Start processing
If you talking about ground control points, they are not needed for processing any images in Pix4D unless you need centimeter-level accuracy. It is not an absolute necessity.