Yes, a guided LSD session as a couple is possible. In settings that use a legal LSD analog and prioritize safety, a facilitator can help you focus on individual inner work first and then guide a shared conversation near the end. For a clear overview of how such sessions are structured, see this page at Triptherapie.
A typical flow is build-up in the first 1–2 hours where some talking is still feasible, a 2–5 hour peak that is mostly introspective, and a final integrative phase when communication usually becomes easier and a gentle, structured dialogue can work well.
Plan ahead: align on intentions, how to handle it if one of you has a tougher moment, and whether you want a primarily shared experience or two individual journeys that meet later. Consider whether psilocybin or separate sessions might suit you better. Only participate where it is legal. I cannot verify your local laws.
If there is active conflict or mistrust between you, consider starting with individual work, since these experiences can intensify what is already present.
I hope this helps.