The following is the birthday card I made:

Step 1: Draw a birthday cake pattern on A4 paper.

Step 2: Cut along the edge of the birthday cake pattern.

Step 3: Stand the cut pattern along the crease.

Step 4: Draw decorations to celebrate happy birthday.

Step 5: Use glue to attach the A4 paper to the pink cardboard.

Step 6: Negotiate blessings on pink cardboard and attach decorations.