I understand you're looking for (often referred to as version 0.980 or 0.9.8.0 ). Here's what you need to know:
If you're already running a previous version of Space Engine, you can update to 0.980 by following these steps: space engine 0980 download upd
CURRENT LOCATION: PROCEDURAL SECTOR 88-ZETA. OBJECT: UNCHARTED GAS GIANT. SpaceEngine 0
Where to download legacy versions like 0.980? : r/spaceengine space engine 0980 download upd
The official SpaceEngine website's Old Versions section.