First, welcome to AND!
I am looking forward to reading more about you and your interaction with horses, but I think it's great that you are asking a question already. If you are not familiar with the AND approach yet, you can check out this introductory post on
AND groundwork. This does not provide a step-by-step plan, but it might give you some general ideas already on how the problem of a "lazy" horse could be dealt with. My reply will also be a bit unspecific, because for me there are a few steps to consider before asking how to get engagement in a specific situation - for example the question of how to get engagement in general. And as I know nothing about you and your horse yet, I also don't know how you are interacting with them. So bear with me for starting at the very beginning.
What helps me a lot when deciding what to do or not to do in interacting with my horses is to put myself in their position mentally and ask how I would like a particular situation. For example, how would I like running circles around someone who tells me to do so, while he is standing in the middle, watching how I move and giving commands, and perhaps even threatening to impose negative consequences on me in case I am lazy or my moves don't please him. In case I feel okay about the possibility that my horses also feel that way, I can simply go on. If not, I have to ask myself what would make the situation better for myself if I was the horse.
For me personally, the most important realization in getting more engagement from my horses was that I cannot be lazy and uninspiring myself, and at the same time expect them to be highly motivated. Although this sounds very simple, I find myself confronted with that same issue again and again. In my experience, most horses do not find it very interesting to run circles around someone. They are, however, willing to do this for me if it is embedded into an interaction that is fun in general. That is, if we play the way they like and then I ask for a few circles, they are mostly okay with it and then also put a lot of effort into it.
Now there are several ways to get horses to enjoy the interaction with humans more, to be more attentive to a human's body language and to be more engaged in the training. They have been discussed in hundreds of posts in this forum, and I can direct you to some of them if you want. However, I feel that before that there is a more fundamental decision, or at least for me there was: Do I want to embrace the idea of my horse being the master of his own training? I think this is an important one, because it shapes the more specific questions to be asked afterwards, and the steps to consider in helping a horse to be more engaged in a particular situation.
Looking forward to reading from you.