Can I use the unpartitioned space to expand /home directory space?

  linux, question

When reading Brother Bird’s book and installing ubuntu, it is recommended to reserve some hard disk space without partitioning, leaving 15G without partitioning. At present, there is not enough space in the /home directory. I wonder if I can expand the /home directory space with the 15G that has not been partitioned, and ask the great god to answer it. I’m afraid I’ll have to reinstall it if I make a mistake. . .

If the partition is lvm, it can be expanded.