You can format a USB drive in Ubuntu using the following steps:
- Insert the USB drive into the computer's USB port.
- Open the Disks utility by clicking on the Dash icon (the Ubuntu logo on the top-left corner of the screen) and typing "Disks" in the search bar.
- In the Disks utility, select the USB drive that you want to format from the list of drives on the left-hand side.
- Click on the "Format Disk" button on the top-right corner of the window.
- In the "Format Disk" dialog box, select the file system you want to use for the USB drive (e.g. FAT, NTFS, EXT4).
- Enter a name for the new partition (if you want to give one).
- Click on the "Format" button to start formatting the USB drive.
- Wait for the formatting process to complete. Once it's done, you can close the Disks utility and safely remove the USB drive from the computer.
Note: Be careful while formatting the USB drive as this will erase all the data on the drive. Make sure to backup any important files before formatting.