No. District of Columbia does not have a prelicensing education requirement. You are free to take the exam without taking a prelicensing course. However, the exam is difficult and it is recommended that you solidly prep for the exam.
We have excellent National courses that do a great job at prepping for the National portion of your exam and for the general portion of your state law exam content. However, a small portion of your exam has content very specific to your state and you do need access to that material to fully prepare for the exam. You may have access to the District of Columbia specific rules and regulations from your recruiter or from other exam prep materials that you purchased or have been given.
We recommend that you supplement our National courses with that state specific material to best prepare you for passing your insurance exam.