Error Inputing the data from the field

hi guys I am new to Ionic so please help me out. I am creating an android application where a user has to input some value into certain fields and that value will be passed along to the server’s database.
But when I inputted the values it is not retrieved in the function. It shows undefined.
my HTML file:

my .ts file:

I tried manually inserting the data into variables. since all my inputted data is containing in the todo{} array.

my console log

In your postParam object, there is problem… FIX may be as follows:::
let postParams = {
name :,
mobile :,