It's hard to tell from the summary (probably intentionally so), but it sounds like it's the author who wants to go to the conference - it's not something his employer wants to send him to. There happens to be training he can take there, and the employer is willing to foot the bill on that. And the author is using that to falsely imply that he's going to the conference to get the training, therefore his employer should pay for the conference as well.
If the employer wanted him to go to the conference, they would be sending him there and paying for it. If they wanted him to get training, they would be sending him to training and paying for it. If they wanted him to get training at the conference, they would be sending him to both and paying for both. Frankly, I think his employer is being mighty generous offering to pay for the training he's taking because he wants to, not because they required or requested it.
If the author feels this conference is critical to his ability to do his job, and his employer is not willing to send him there, then he needs to do a better job explaining (to his employer, not to us) why it's so important for him to go to this conference. It's common for a particular employee to be the company's subject matter expert in a particular field, and a good manager will know to trust the employee's judgment in those cases. If author has not made such explanations before, try breaking it down into monetary cost/benefit. Business-types love that. e.g. Show why the tech will become of key importance in the future, lay out the cost to hire an outside consultant expert in the tech, and compare it to the cost of paying for your conference, travel, and training to make you expert in the tech.