On some iOS devices, if you have enabled content restrictions, the device will block access to the CoughDrop app unless you override that option to allow access to CoughDrop.
Add CoughDrop to the Approved Content List
In order for a device to be able to open CoughDrop when content restrictions have been enabled, CoughDrop will need to be added to the approved content option on the device.
This override will need to be performed on each individual device that is working to access the CoughDrop app if content restrictions have been enabled on that device.
On the iOS device, open the settings page. Then select "screen time" from the options on the left of the screen. You will need to note that this is your device.
Next, choose "content & privacy restrictions" from the options on the screen time page and then hit "content restrictions" from the section near the top of the screen.
You will see a section titled "web content." Tap the link in this section.
Most devices will have "unrestricted access" selected, but if content restrictions are turned on then the device will likely have "limit adult websites" or "allowed websites only" selected in this section. To add CoughDrop as an approved website, tap the "add website" option under the "always allow" heading.
Now enter "http://localhost:4321" in the approved field and hit "done." This will enable access to the CoughDrop app using the device.