The frog needs warmth , humidity , water source. , a place to hide to lessen stress.

You will need these basic things
A thermometer/hygrometer get the kind that can be placed with suction cups
so you can place it anywhere in the tank.

You need a good screen lid that will allow light and air to pass.
you can also use a cloth to cover part of it to keep heat and moisture in.

A heat source can be as simple as a floor lamp that has a flexible neck or a desk lamp
with a regular 60-100W light bulb depending on how cold it is in your home.
you need to keep the tank around 80F and the humidity above 75%

If you keep the paper towels moist that won't be an issue.
And change the paper towels and clean the water dish daily.

A water dish that is easy for it to get into. for now a dish that is 1/2in deep is good.
That should be filled with dechlorinated water. You can use the same dechlorinator for fish ( also the paper towels )
Do not use untreated tap water. no matter if it is city or well water.

As for a hide you can use a coconut hut or a half round log both can be found at
a pet store. This will be one of the best things you can do. stress is a big deal for these guys.

As for force feeding.
before you do that try a honey solution soak.
Honey is anti bacterial and will give some much needed carbs that can boost
its appetite and give it some energy to try to eat.

I use a clean 1quart Chinese take out container with a lid for my soaks.
Use a pen or a Phillips screw driver to poke some holes in the lid from the inside out
so the sharp edges are not inside where the frog is.

Use unflavored plain honey only two to three drops in just enough water to get the shoulders
of your frog. ( you don't want to drown it)
The water again should be dechlorinated and warmed to 80F.
Have another container with just dechlorinated water as a rinse. at the same temp 80F (nothing is more shocking than a cold dip.)

Let it soak for 5 to 10 min. in the honey mixture.

then put it in the rinse for a minute or two.

Put the frog back in the hospital tank and let it settle for an hour or so
and offer food and see if it will eat.

Before you go much further I hope that you have taken the frog to the vet.

I strongly suggest that you get a vets help.