this is a simple phone holder that prints with no supports it fits my bed headboard which is 3.5 inches thick but you can adapt it to thinner headboards with a little foam of cardboard in the rear to suck up the excess space , its wide enough to support a galaxy note4 and holds it securely , i also added 2 of Velcro dots ( soft side ) to the inside where the phone is to hold it without having to worry about scratches. 

these are the dots i used ( not a affiliate link just giving and example ) you could also use these to hold the bracket in place but i like to be able to move it easy 

 https://www.amazon.com/VELCRO-Brand-Adhesive-Projects-95215W/dp/B0B8ZYG94N/ref=sr_1_1?dib=eyJ2IjoiMSJ9.xYYepHzPSKYdLpW6X0IRGAw4THpn8vlrGAGhiksHPmwcDmxTWGtLKeDj1eazt3UhKWqZnxkSHxBf6XFpQ2ahbthAeQEXVup41gvrqnJRst4yOlueBDW4GcDjU8mZ-Kuc0OiP2KFBelho3WfzQRZ4r4EJYmbxyww5Ki-iThLM--uoZZ5g9Wyv8OMz__RRiQ8enc_6NRb25tsbixYYe3s4oKkPvdHZ6AsJQseJvwHNbI8.rxxj9l6MhatWa8VFg4zuMpS-zQY-ryojMptQYRbQZkI&dib_tag=se&keywords=velcro+dots&qid=1748897845&refinements=p_85%3A2470955011&rnid=2470954011&rps=1&sr=8-1