u/Paprikaorama

Hi everyone, I’m looking for some advice about my Belgian Malinois Shila. She is a female and now almost 6 months old, been with us for 3 months now.
She has no problem peeing and pooping in our own yard. She is fully house-trained and knows the commands for both. If I tell her “go potty” or “go pee” in our yard, she will do it without any issues. The problem is that she does not relieve herself anywhere else. During walks, in parks, or even when visiting friends or family who have yards, she becomes interested in everything around her, sniffing, exploring, watching things, but she simply will not pee or poop. She is not even complaining based on her behaviour, but as soon as we are back home she immediately pee and poops, which shows that she was holding it until we are back. It seems like she only feels comfortable using our own yard. The commands that work perfectly at home have no effect in other locations.
My main concern is travel. Right now, I can’t imagine taking her on a longer trip because I worry she will keep holding it for too long. I don’t want her to develop any health problems from refusing to urinate or defecate in unfamiliar places.
Has anyone dealt with something similar? How did you teach your dog that it’s okay to potty in different environments? Are there any training exercises or gradual exposure methods that worked for you? Any advice would be greatly appreciated. Thank you!