Hi @clairebre,
I would request you install PostgreSQL 9.6 or higher in your system and try using the instructions @Knut_Staring has shared. @Lars had shared some release notes you can check out on 2.31 upgrade notes that specifies the use of PostgreSQL 9.6 or higher version.
I will also try it out on my machine and see if it’s successful based on the information offered. Kindly let us know if this works out well.
Best,
James.