To resize block store in DigitalOcean, click on the droplet to which the volume is attached.
Click on more -> Resize volume as shown below:
You are now able to select the new size of the volume and initiate the resize. DO will inform you that the resize has been completed, but this is only part of the process to complete the resize. You will need to login with root and issue these commands to complete the resize:
This will show you what the path is for the volume. In our case the path is /dev/sda
lsblk --fs /dev/sda
This will show you what the filesystem of the volume is.
This actually performs the resize of the volume and completes the process.
You can then view the size of the volume again by running: