When i click on Add money on my account page it will not accept

See -> Add money to your Apple ID balance

Add money to your Apple Account balance - Apple Support (IN)

See also ⤵️ 

App Store & iTunes gift card:

Apple Gift Card - Apple (UK)

What you can buy with your Apple Gift Card or Apple ID balance

What you can buy with your Apple Gift Card or Apple Account balance – Apple Support (UK)

Give apps, music, films and more from Apple

Give apps, music, films and more from Apple – Apple Support (UK)

How to redeem your Apple Gift Card or App Store & iTunes gift card

How to redeem your Apple Gift Card or App Store & iTunes gift card – Apple Support (UK)

• In the United States, when you redeem a gift card to your Apple Account balance, the balance might appear in Apple Wallet.

(outside the United States) When redeeming a gift card, (1) the amount will be credited to your Apple ID balance and (2) then you need to set your Apple ID balance as your default payment.

(1) See -> Check your Apple ID balance

Check your Apple ID balance – Apple Support (UK)

(2) See -> Change, add or remove Apple ID payment methods

Change, add or remove Apple ID payment methods – Apple Support (UK)

Where to buy a physical Apple gift card:

Actually, you can buy an Apple gift card at many places, it depends of course on where you live.

At an Apple Store or an Apple Authorized Reseller in your region certainly, but also at a good bookstore, supermarket and/or drugstore.

The gift card for everything Apple -> Apple Gift Card - Apple

This 'universal' gift card was launched in the US at the end of July 2020.

Since June 29, 2022, a number of European countries have been added, including Germany, France, Italy, Spain, the UK and the Netherlands.

(on macOS) Click Add money -> iTunes Store opens in iTunes.

Check also ⤵️

If you can't redeem your Apple Gift Card or App Store & iTunes Gift Card

If you can't redeem your Apple Gift Card or App Store & iTunes Gift Card - Apple Support

• You can't redeem Apple Gift Cards or App Store & iTunes Gift Cards outside the country or region of purchase. For example, if you bought an App Store & iTunes Gift Card in France, you can't redeem it in the App Store in the United States.

Terms and Conditions for Apple Gift Cards and Codes, Apple Account Associated Balance, and Content Codes

Legal - iTunes Gift Cards and Codes - Apple 

❗️About Gift Card Scams

About Gift Card Scams - Official Apple Support

If you add money to your Apple ID balance, It would take about 1 to 3 business days in order to process.

See -> Check your Apple ID balance

Check your Apple ID balance – Apple Support (UK)

If you're still unable to update your payment method, Contact Apple Support.