I resized by droplet, it is marked as resized, but when I log into it half an hour later, it still seems to be the same size. What am I m...

I have resized my droplet’s disk from 40 to 80, and now it looks like this:

doctl compute droplet list
ID           Name               Public IPv4        Private IPv4    Public IPv6    Memory    VCPUs    Disk
1234         jenkins            x.x.x.x            10.132.0.3                     4096      2        80

After waiting 30 minutes, when I log into my droplet I am expecting the disk size to be 80, but it still seems to be 40:

ssh root@x.x.x.x
Filesystem      Size  Used Avail Use% Mounted on
udev            2.1G     0  2.1G   0% /dev
tmpfs           412M   43M  369M  11% /run
/dev/vda1        42G   42G     0 100% /
tmpfs           2.1G     0  2.1G   0% /dev/shm
tmpfs           5.3M     0  5.3M   0% /run/lock
tmpfs           2.1G     0  2.1G   0% /sys/fs/cgroup
/dev/loop1       43M   43M     0 100% /snap/snapd/20290
/dev/loop2       72M   72M     0 100% /snap/lxd/22753
/dev/vda15      110M  6.4M  104M   6% /boot/efi
/dev/loop0       67M   67M     0 100% /snap/core20/2015
/dev/loop3       43M   43M     0 100% /snap/snapd/20671
/dev/loop4       97M   97M     0 100% /snap/lxd/24061
/dev/loop5       68M   68M     0 100% /snap/core20/2105

I would expect to see something like this:

...
/dev/vda1        80G   42G    42G 50% /
...

But I’m still seeing

...
/dev/vda1        42G   42G     0 100% /
...

Wondering if I’m missing something on how to resize a droplet’s disk.