Ionic error connection to bank Phppgamdin

Hello, my ionic is giving error, I am trying to connect to phppgadmin on my school's server, I am using a php api that will connect and return a list of data from a given table in a JSON string that will appear in the browser, then a provider will pick up this JSON string and interpret this string by actually transforming JSON into an array that will call the home.ts page to put the JSON data into an array. this array will be used to make a sort of table. was the only solution I had to connect to the web bank.

Thisistheprovider,thereisanerrorinitsayingthat.getisnotarecognizedmethod,whatcoulditbe?

Thisistheapi,atthemomentitisworking.

Andthisisthehome.tspage,thereisalsoanerrorsayingthat.subscribe()doesnotexistincontext,whatcanitbe?

And the last mistake is this.

Pfvr, help me in these mistakes! and if you have another way to connect to the bank you can talk pfvr !!

I've also been thinking about how I could change and delete data using such an api, since I would have to do data transfer to the server, how would it look like?