Where are promo train tickets valid in the Netherlands

I'm currently part of a group of scouts in Delft and we (12 aged 15 through 17 & 2 over 18s) and we are trying to get to Amsterdam as cheaply as possible. We have looked at group tickets (https://www.ns.nl/producten/en/losse-kaartjes/p/ns-groepsretour) but these appear to need printing so aren't practical (we are camping and don't have a printer) we have some mobile phones (not enough for 1 each - would it be possible to show the tickets on these?).

However, I then found a link to what is described as a promo day ticket at 12.50EUR (https://www.ns.nl/producten/en/s/dagkaart-juli-1606072) but I'm struggling to find any information, where are these tickets valid for and is there any time restrictions? And would we need to print off something to use them?

Apologies for the formatting as we are sending this from a mobile over dodgy WiFi. Huge thanks to anyone who can fix it.

Edit: quick additional question, what is the ideal payment and it used with a UK credit card?

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Can I use my train ticket at any station?

Tickets that have been purchased with an \u201cany available route\u201d option can be used with any train company that operates between the stations you wish to travel. Any time tickets are the most flexible and can be used on any train on the chosen day of departure for the journey you have booked.

Are trains free in Netherlands?

Train tickets and costs in the NetherlandsThere are two ways to pay for your train travel: either use your OV-chipkaart credit or buy a ticket. You can buy tickets online or at a ticket office or machine at the station. One way to make train travel cheaper is with a subscription.

What is intercity Netherlands?

The Intercity Direct is a fast domestic Intercity rail service using modern ICR single-decker carriages similar to the above ICM layout. It only serves the Amsterdam-Schiphol-Rotterdam-Breda route using the Dutch high speed rail track. The international Intercity Brussels service continues on to Antwerp and Brussels.

Do they check train tickets in Netherlands?

Trains in the Netherlands: your ticket will be checked Almost every time I take a train in the Netherlands, my OV card or ticket is checked. There are no exceptions made if you're a tourist and were confused about how the trains in the Netherlands work: you will be fined if you don't have a valid ticket.

How to book NS Train ticket with discount? 🎫 | Boarding Train in Netherlands for the first time📍🚆

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