How to auto categorise bank narration into category and sub category using keywords?

I am making an Excel sheet for daily expenses. I copy and paste transactions from my bank account row by row.

My columns are:
Date | Type | Narration | Income | Expenses | Balance

Now I want to add two more columns after Balance. One for Category and another for Sub Category.

What I am trying to do is this.

On Sheet2, I want to create a small reference table where I define keywords and assign them a Category and Sub Category. Then based on the Narration text in Sheet1, it should automatically classify.

Example narrations:

Apos Chv43069 Inlet
Opos Paypal *4
Free Interac E-Transfer
Opos 1.00 Thinkiqacademy

If narration contains:

Apos → Category: Games, Sub Category: Subscription
Opos → Category: Payments, Sub Category: Subscription
Interac → If it is on credit side, then Category: Income, Sub Category: Loan or Wages (depending how I define it)

So basically I want Excel to look for certain words inside narration and then assign category automatically.

I was thinking to use a reference table in Sheet2 and maybe SEARCH or something similar, but I am not sure what is the cleanest way to do this.

Goal is to organise my expenses properly so I can see where my money is going and manage it better.

What would be the best way to set this up?
Excel version: Microsoft 365 for Mac, Version 16.106.1