It may happen that the IP service would throw an 429 error code
The user shouldn't be blame for that and some data should be displayed anyway instead of printing the blank page

Setup jasmine or mocha and create basic tests cases, because why not?

Make table look good both on desktop and mobile

Some users may want tot delete their IP entry from this website, so maybe a delete button near the entry -with their IP would be a nice improvement.
There should be IP check at the backend to prevent deleting all the entries by teenage hackers

A few mock entries would improve development experience. There isn't always need to setup mongo.

Running the app locally requires now to setup the mongodb database and paste the uri in the .env file without instructions.
Some default local env file and database setup instructions in README.md would help new devs contributing to the project.

There are sqlite3 and sequelize that aren't used.
The best options is to use yarn remove sqlite3 sequelize