When you use the trial feature for premium plans you can promote a plan to be a premium plan a.k.a. Project for the web project, to get the additional features of timelines, goals, Copilot and more! This feature will also be coming to new Planner for all basic plans, but probably not until the summer 2024. For now, there is a work around using a specific Url with the Plan ID of the basic plan added - then the magic happens, and you get a premium plan (some limitations apply - see the docs linked below).
A basic Planner plan you a board view and a grid view, and some charts, but if you need more then time to look at making a premium plan from it.
The workaround until the in-app feature becomes available is to craft a Url that starts with your Project for the web Url, including locale and tenant, adds some specific parameters and adds on the plan id. It will look something like this:
https://project.microsoft.com/<your tenant name>.onmicrosoft.com/en-US#/hubnew?importPlanId=<your Plan ID>
Hopefully you know your tenant name, or just navigate to project.microsoft.com and it should complete the Url up to the locale part (en-US in the able example) once you have signed in. To this you add the #/hubnew?importPlanId= part and then the plan id. It isn't easy to find the plan id in Teams (but if you know your way around F12 Dev Tools you can find it) but easier to just look for your plan at tasks.office.com and open it - then the Url will contain your plan id. In my case the Url in Planner is:
https://tasks.office.com/brismith.onmicrosoft.com/en-US/Home/Planner/#/plantaskboard?groupId=d132c3ce-e77b-7bfc-a703-3aceaed05a37&planId=q_E7IvbSGkCD1f537UPBUGUADys7
and the final part is the plan id - after planId= - so q_E7IvbSGkCD1f537UPBUGUADys7
Adding this to the project Url and the parameter part gives me a full Url of:
https://project.microsoft.com/brismith.onmicrosoft.com/en-US#/hubnew?importPlanId=q_E7IvbSGkCD1f537UPBUGUADys7
Once I have this, I can paste it into my browser, log in if I don't already have an active session, then the magic starts!
After a short while you will see this screen briefly:
then you will see the background change to your new premium plan and the dialog changes to:
Be sure to review the document - the "Learn more" link goes to this article https://prod.support.services.microsoft.com/en-us/office/import-a-plan-into-a-project-for-the-web-01... and probably the most important section relates to the task limits. Only 950 tasks will be imported into your premium plan. See the other sections too to be sure you get what you need:
But that's it. Hopefully that will help until the UI has an option to import basic Planner plans to the premium experience so you can then use all of the extra features of premium plans:
and use it in new Planner too - under My Plans:
Any questions - add them below and I'll get back to you.