You'll be using the Lineup Settings menu found when you click the Gear button labeled "Draft", see the graphic below:
5.0 Set Up Lineup Requirements
We need to tell the Dominator how many players start at each position in your league - this is under the Lineup Settings menu in the Gear Button menu. See the graphic below:
Draft Dominator assumes that your league starts one quarterback, two running backs, three wide receivers, one tight end, one kicker, one team defense and one RB/WR/TE flex position. However, if tight ends are lumped in with wide receivers in your league, you'll need to zero out wide receivers and tight ends in the Lineup Settings, and instead tell Dominator how many total wide receivers and tight ends start in your league (usually three or four depending on the league) in the WR (TE Eligible) drop down menu. If there is no flex position in your league, you'll need to use the drop down menu to zero that option out.
If quarterbacks are included as a possible flex position in your league, you need to zero out the preset Flex: RB/WR/TE from one to zero and instead put one in the Flex: QB/RB/WR/TE drop down menu/box.
However your league's lineup requirements work - when you add up all the numbers on the Lineup Settings page, that number should be equal to the number of starters required in your league. No matter how big/deep your benches are, there is a required number of starters for any given week (even if you have a flex position that might vary the number of starters at any given position from week to week). Cross-check with your league rules to make sure you have the correct number of starters selected in Lineup Settings.
Once you are sure the Lineup Settings are correct, click the green Done button at top right.