Is there any means to find my iPhone by using someone’s iPhone?

On another person’s iPhone, open the Find My app and select the 4th option at the bottom categories on the screen. Scroll all the way down and you will see a link to find your iPhone using their iPhone. “Help a friend”. You click that link and sign into your account and then you can find your iPhone.

Using any web browser, login into iCloud.com and use Find iPhone