True strike chance to hit

Hi

can anyone please help me I can not seem to add my chance to hit (CTH) bonus from my +1 bow to my customised true strike action.

i have 18 dex and 19 int and i am alvl 4 arcane trickster rogue.

my normal bow chance to hit is 4 from dex 2 from proficiency and 1 from bow = 7

my true strike only appears as 6 even thought the maths should be the same.

i can not amend the CTH to add the bow bonus in dnd beyond.

can anyone please help me

thanks

You won't be able to add it to the custom action, because it doesn't take the weapon into account and there's no option to add bonuses to the attack rolls. 

I think the simplest way to solve this would be to add a separate Longbow, +1 and just customise the 'To Hit Bonus' and 'Damage Bonus'. If you absolutely need to have the damage type show up as radiant, you could create a homebrew version of the same item with the 'Replace Damage Type - Radiant' modifier.

It should be noted that the die roller buttons on the D&D Beyond character sheet don't support multiple damage die sizes in the same roll, so unless you're using a weapon with d6 damage dice, you will not be able to get proper support for True Strike on a single action anyway.