David Klee shows how to migrate the tempdb database when running SQL Server on Linux:
We previously created a folder at /var/opt/mssql/data/tempdb01 for these files. Moving them is straightforward, once you know the file system structure. The following commands will move them to the new location, and I also add additional files to equal the four vCPUs I have on this SQL Server VM. The file growth is my model database’s default of 64MB for this instance. Do as you would normally do with SQL Server on Windows with tempdb file counts and separation of duties for your workload.
Read on for the process. As a general spoiler, the “how to do this in Linux” answer is usually pretty close to the same as the “how to do this in Windows” answer, at least once you get into Management Studio.