[Vuejs]-Why cant I save data to database?

I have no idea what kind of object "this" is, but are you sure that this.title has been set to something, and is not empty?

Seems like you don’t set the form data correctly. The docs suggest something like this for the browser:

const params = new URLSearchParams();
params.append('param1', 'value1');
params.append('param2', 'value2');
axios.post('/foo', params);