Hello! It sounds like you're having an issue receiving a verification code or PIN from the “Randstad: Jobs for Workers” app. Let's try to troubleshoot this together.

1. Double-Check Phone Number: Ensure that the phone number you entered in the app is correct. It's a common issue that can prevent the delivery of text messages.

2. Signal Strength: Make sure you have a good cellular signal on your iPhone. If the signal is weak, try moving to a location with a better signal strength.

3. Check Message Filters: Sometimes, messages or calls can be filtered out as spam by your network provider or by the phone itself. Check if there's any filtering system that might have blocked the message.

4. Restart Your iPhone: A simple restart can sometimes resolve glitches, including issues with receiving text messages.

5. Normal SMS Functionality: Make sure you are able to receive messages from other sources. If not, there might be a service issue with your carrier.

6. Support Contact: If you continue to experience issues, you may contact Randstad directly for further assistance. Here's their contact page. In some cases, an alternative method such as email verification can be set up.

Please try these steps and let me know if you're able to resolve the issue or if we need to explore other options.