Teleport

For getting out of the Toad, the simplest way would be to teleport . (you don't need to see where you want to go)

Dominate

Another way would be to dominate the Toad to spit the swallowed character (for example with dominate beast). And if the DM argue that you cannot force the toad to spit the character, you could force it to open its mouth as wide as possible.

Paralyse

If you give the condition paralyzed or unconscious to the Toad, you could open its mouth and try to extract the character (you could to that using a wand of paralysis)

After that, I the other options I see depend on your DM. You could try to force the Toad to vomit by creating a reaction in her stomach (by creating gas or fire inside it [or disgusting material that would provoke the toad to gag])

Yes, you have several solutions to escape from inside the toad or to be extracted from outside with the help of other party members.

From inside the toad

For getting out of the Toad, the simplest way would be to teleport . (You don't need to see where you want to go)

Other solutions (subject to DM approval)

After that, I the other options I see depend on your DM. You could try to force the Toad to vomit by creating a reaction in her stomach (by creating gas or fire inside it [or disgusting material that would provoke the toad to gag])

From outside the toad (other party members helping)

Enchantment

Another way would be to dominate the Toad to spit the swallowed character (for example with dominate beast). And if the DM argues that you cannot force the toad to spit the character, you could force it to open its mouth as wide as possible.

A low level solution would be suggestion.

Paralyze

If you give the condition paralyzed or unconscious to the Toad, you could open its mouth and try to extract the character (you could to that using a wand of paralysis). As noted by @Mindwin, this solution could be subject to the DM ruling.

Getting out

For getting out of the Toad, the simplest way would be to teleport .

Another way would be to dominate the Toad to spit the swallowed character (for example with dominate beast

After that, I the other options I see depend on your DM. You could try to force the Toad to vomit by creating a reaction in her stomach (by creating gas or fire inside it [or disgusting material that would provoke the toad to gag])

As it is not explain in the rules, this would depend on your GM. But as marked in the wild shape description, I would revert the process:

You choose whether your Equipment falls to the ground in your space, merges into your new form, or is worn by it. Worn Equipment functions as normal, but the DM decides whether it is practical for the new form to wear a piece of Equipment, based on the creature's shape and size. Your Equipment doesn't change size or shape to match the new form, and any Equipment that the new form can't wear must either fall to the ground or merge with it. Equipment that merges with the form has no effect until you leave the form.

It is about the equipment and only concerning the process to transform from humanoid to beast, but I think it could apply to this situation. The character swallowed would fall on the ground in front of the druid.

Teleport

For getting out of the Toad, the simplest way would be to teleport . (you don't need to see where you want to go)

Dominate

Another way would be to dominate the Toad to spit the swallowed character (for example with dominate beast). And if the DM argue that you cannot force the toad to spit the character, you could force it to open its mouth as wide as possible.

Paralyse

If you give the condition paralyzed or unconscious to the Toad, you could open its mouth and try to extract the character (you could to that using a wand of paralysis)

After that, I the other options I see depend on your DM. You could try to force the Toad to vomit by creating a reaction in her stomach (by creating gas or fire inside it [or disgusting material that would provoke the toad to gag])