It is important to note that docker containers and unikernels are fairly differernt and are not at all the same thing. Most notably a docker container typically has a large userland that can run many different programs whereas a unikernel can only run one. Not only that but a unikernel is single process (however has support for multi-threading).
In practice this means that sometimes there are tweaks that need to happen for you to run something as a unikernel vs a container, these tend to come with substantial security and performance benefits.
Many applications can be imported from docker containers into unikernels quite easily as shown in:
https://docs.ops.city/ops/packages#create-a-package-from-docker
On can set the arguments for the package that is created from the docker export as they sometimes will differ from a Dockerfile.
For example to export a nextjs docker container to a unikernel package:
ops pkg from-docker njs2 --copy --file /usr/local/bin/node -a app/server.js
ops pkg load --local njs --nanos-version=3c1fb76