To buy a custom make one will cost a bomb, but here is one easy way to make it with card board, a bolt & 3 nuts.
Step 1: Determine the Dimension
*Measure so that the stand is in the middle of the panel.
2- HALF cut the bending edge...Do NOT cut through, it is meant to bend.
3- Tape along the HALF cut area so as to prevent further tearing.
4- Measure the location of the hole for the bolt to go through.
5- Use a hole puncher to make the 2 holes (for M6 Bolt)
Step 2: Make the Platform for Attaching Solar Panel
2- Also do a HALF cut along the bending edges.
3- Tape the HALF cut area.
4- Use some double sided tapes if you require on the top part fo the platform.