How to allocate free disk space, when disk utility doesnt see it?

Hello danil10,

Steps to manage your partition can be found in the following user guide:

"Delete a partition

WARNING: When you delete a partition, all the data on it is erased. Be sure to back up your data before you begin.

1. In the Disk Utility app  on your Mac, select a volume in the sidebar, then click the Partition button in the toolbar.
2. If Disk Utility isn’t open, click the Launchpad icon  in the Dock, type Disk Utility in the Search field, then click the Disk Utility icon .
3. In the Apple File System Space Sharing dialog, click Partition.
4. In the pie chart, click the partition you want to delete, then click the Delete button .
5. If the Delete button is dimmed, you can’t delete the selected partition.
6. Click Apply.
7. Read the information in the Partition Device dialog, then click Partition.
8. After the operation finishes, click Done."

Should the behavior persist we recommend reaching out for additional support in your region. You can do so here: Get Support

Take care.