What is the highest Mac OS with guaranteed compatibility with LibO 7.0.31?

I have a Mac OS 10.13.6 and I’m running LibO I have thousands of important docs saved in LibO and would be devastated if I lost them or could not open them. For that reason, I have not updated my Mac OS but am now being told that 10.13.6 will no longer be supported. I am very nervous about updating. I need to guarantee nothing will happen to my LibO docs before I take the plunge.