When asked what does motivation look like to you? How does it feel internally? What is your definition of it? Common answers are "Someone who regularly does a task that takes work (gym, cleaning the house, doing the dishes)" or "the desire to take steps to accomplish a goal". These answers speak to habits that have formed and/or a sudden urge/dedication to do the thing.
While it's nice to wait for the dedication to do the thing to arise, for those who are autistic, adhd, or live with other neurodevelopment mental health challenges or even traumatic brain injuries, it isn't a muscle that can be developed in the same way someone who is neurotypical can. We as a society have a tendency to look at external forces when something works or doesn't work, not looking at cognitive wiring. Let's take a moment and suspend what we believe is motivation and instead view it as an ability to focus for the duration of a task. People without neurodevelopment adversity learn in school how to train their brain to focus on tasks at hand and by adulthood are capable of doing mundane or boring chores/tasks when they set their mind to it and gain satisfaction from the completion of the task. For those with differently wired brains, focus isn't something that is learned in school, our mind is constantly over or under stimulated and searching out ways to find equilibrium. Additionally ADHDers also experience a dopamine deficit and seek out ways to meet this (sugar, tv, video games, etc), making mundane tasks that much harder to accomplish.
Switching to "what does focusing for an extended period of time look like for me?" can be helpful for all neurotypes as it is non-pathologizing and steps away from the ableist lens of "just do it" or "why can't I just do it?" and shifts instead to what helps me focus? For some it may be "I need a clean workspace" or a noise free environment. With neurodivergences, it will likely be tuning into is my mind overactive and not allowing me to narrow down my focus enough (think I have 10 ideas right now and im scanning through them like channels on a tv) or am I not stimulated enough cognitively? If it's the former tuning in to what is needed to lower the mental noise, the latter may require background noise or doing more than 1 thing at a time (talking on phone while doing dishes, tv or music on).
Let's be self-compassionate and look to understand our internal states, instead of criticising. What you're experiencing in any moment is a signal or cue that can help you understand yourself better!