first create a cylinder,
then duplicate it twice, rotate two of them to 90 degress in the x and y axis, but depending the position you will put them,
then
enable snap during transform in increment, then go to right,top view to move each one (in this case only 2 of them) them precisely in the grid,
then select one and hide it, then select the other and perform a boolean in edit mode, select union option, then start doing some clean up of faces,edges, and merge vertices by distance if necessary...
then unhide the other cylinder, and do the same steps...
Final Result
