It should be stated that your project requires DOTween, paid or not.
IF the DOTween actions are free (you would have to contact both Unity and the DOTween publisher to verify), maybe you might add the free actions, but that's all you can put and I'm not even sure of that.
You must make the user buy or get and then download the assets by adding the proper links in your own Asset Store's item page and perhaps also add a correct install file in your own project, a readme or something.
You should do a test with an empty project and reproduce the steps that a user would go through. The moment your project would be installed, its DOTween actions would be looking for the DOTween assets that would be missing and you'd get errors, that's a bad thing to happen.
You might pack parts of your project that use and contain DOTween related material (GOs with FSMs using these actions, plus the actions' respective scripts themselves) so that the user needs to manually import them, with this package being in a subfolder alongside the readme file.