How can I disable all purchases except apple services?

Brakeforcommonsense wrote:

Show me where???

Turn on Screen Time

Use Screen Time on your iPhone, iPad, or iPod touch - Apple Support

• Go to Settings > Screen Time
• Tap Turn On Screen Time, then tap it again
• Select This is My [device] or This is My Child's [device]

I wouldn't bother setting a passcode. The reason you'd use that is if you were setting up parental controls and didn't want your kids going into Settings and turning those controls back off again …

Set Screen Time Restrictions on Purchases

Use parental controls on your child's iPhone, iPad, and iPod touch - Apple Support

I am guessing that disallowing In-app Purchases will work on your own account – not just on your child's. If it does, here's how you would set it up:

• Go to Settings and tap Screen Time. 
• Tap Content & Privacy Restrictions. If asked, enter your passcode.
• Tap iTunes & App Store Purchases.
• Choose a setting and set to Don't Allow.

You could also change the Require Password setting to Always Require. (I think that one will throw up an "enter your password" roadblock for all App Store and iTunes Store purchases, not just the in-app ones.)

If you ever did want to make an in-app purchase, you could come back here and temporarily relax the restriction.

I believe there is a setting somewhere in Screen Time that you can use to disable the ability to make in-app purchases. If you are doing this for yourself (not a child), you could disable in-app purchases, without setting a special passcode just for Screen Time.

The phone might then bother you from time to time with reports of how much you had used it recently …

it's not hard to cancel subscriptions

If you want to cancel a subscription from Apple - Apple Support

I've never signed up for anything without knowing myself

This is a user helping users with tech questions forum, we are not

apple and apple do not read your posts here

you can give them suggestions using their feedback channel

Product Feedback - Apple

The particular implementation that you want (dropping the request for a credit card number – and forcing apps to ask for credit card numbers directly) is not available.

I described a feature that does exist.

If you want to ask Apple for a feature that doesn't exist today, see

Product Feedback - Apple