As the Pro1 and Pro1-X are A/B devices, the images are inside "payload.bin". The official LineageOS tool to extract them is extract.py, but there are others ...
It might be so on other builds, but not on the official builds for LineageOS 16, 17, 18, 19, 20, nor AICP as far as I can see.
(It might be inside payload.bin though)
Here latest Lineage