@hazardwarning No need to seal punctures on the go. Just have a spare inner tube in your saddle bag. There are also those goo-filled inner tubes you can get that self seal punctures. I think there are various options for puncture anxiety that you bike shop can help you with. You can even get tiny canisters of compressed air that inflate the tyre instantly.
If you have no other option, you can cram your tyre with grass. I’m told it does actually work as a short-term stop-gap.