You are talking about the high and low horizontal bars! It's the kind with three columns and two beams. If so, the specific steps are to determine the location first, then start digging holes, then pour concrete, and finally fill them up. The pit spacing is the length of the beam, of course, it is a little larger. If there are three pillars, you can dig three pits with a depth of 60cm. After digging, try putting the post in. There are no obstacles. Get someone to hold it and start pouring concrete. Finally, smooth the ground around the column with concrete. Note that the column is vertical after injection, not inclined. The beam is also horizontal.