Lateral bracing for steel beam
Are you sure your steel beam is a W16X26?
I doubt that beam needs lateral bracing, because that size beam will support about 31,000 lbs. per foot for a 20’ span. (That size beam can support my entire house and 3 of my neighbor’s houses.)
Lateral bracing is required when a beam is fully stressed (or overly stressed) and you need to keep the beam from buckling and “laying over”. This beam is not overstressed.
If you start drilling holes in the flanges, you’ll weaken the beam...don’t. If you need to attach something, drill holes in the vertical web.