At a minimum I would expect you'd still need a professional lighting setup, a sturdy tripod, the right studio background, a good DSLR (or mirrorless), properly diffused, reflected and toned flash, and the skills to really work with RAW images to get the best possible output. And that's even before we include the skills and knowledge to guide their subject to just the right poses to get the subtle body language right. (Yes, the relative position of your spine and the stress you put on your upper body does affect how comfortable and confident you appear in the final shot. I know that now.)
More than 20 years ago, my boss at the time recommended that I get a professional headshot. We were producing printed[ß] booklets as part of our marketing strategy, and I wrote occasional columns in them. He wanted to have the author's face attached to the pieces. He recommended that I pay for the service myself so that the photos would remain with me. If the company had paid for them, getting them into any other (read: off-work, post resignation) use would have been awkward, confusing and possibly a red flag for the accountant. One of the best investments I've ever made. I paid for three slightly varied versions, and used them actively for about a decade.
As it happens, it might well be the time to get a fresh set.
ß: an anachronism, no doubt