I can't update ios on iphone 5 it is ios 10 on it

If it is a model 5 or 5c = NO

If it is amodel 5s = YES

I have iphone 5s but ios version is 10.3.4 and there is no update to ios 12 available

That is the correct. Your profile mentioned that you have an iPhone 5, not a 5s. If you have an iPhone 5, you have reached the end of the update road with the iPhone 5. It cannot go any further.

If you want to run apps that require a higher operating system, you will need a new phone.

iOS 10.3.4 is the end of the update road for the iPhone 5.

Then identify your model correctly, in Settings>General>About>Model.

What is shown there?

See why in this compatibility chart:

andrzej232 wrote:

I have iphone 5s but ios version is 10.3.4 and there is no update to ios 12 available

Unfortunately, that is not possible. If it is running iOS 10.3.4, it has to be an iPhone 5.

MD298LP/A = Model 5, not 5s

Regards

Giulio

MD298LP/A is an iPhone 5