How should this word be spelt in this context?

If I wanted to write the following sentence on a advertisement leaflet to pro eye a class-

‘Lead by a highly experienced technician’

Should ‘lead’ be spelt lead or led?

The past tense of lead is led so it must be led.

It is not past tense though it is a bullet point saying that the class will be/is lead by a highly experienced technician

I don't know whether you're getting confused with this due to the fact that the past of read is read and so may assume that lead is the same. But in the case of lead all you need to know which one to use is to know how you would pronounce it when speaking. In your example you would say it as ''the class will be led by a physician'', not ''the class will be leed by a physician.''