Should you decide to use an online service instead of going to an estate planning attorney, you may find yourself with a trust but then learn you also need a will, according to the Lake County News in "The difference between a trust and a will."
It is likely that when you pass away you will have some assets that for one reason or another were never put into your trust. Those assets will need to be distributed by your estate and often under the guidance of the probate court. You need a will, so what you want done with those assets can be done.
Often that will is only a “pour-over will” that directs that everything should be transferred to your trust. However, there are other things you might also need to accomplish with a will such as directing who should be appointed as a proper guardian for your minor children. You also might have some assets you do not want to go through a trust for other reasons, for which a will would be appropriate.
An estate planning attorney can advise you on creating an estate plan that fits your unique circumstances and often includes a will as well as a trust.
Reference: Lake County News (Feb. 24, 2018) "The difference between a trust and a will."