You succeed automatically if the target is incapacitated.
However, the text doesn't link to the incapacitated condition. The Shoving section that follows has the same line, where it is properly linked.
(The PHB also has the same lines in the corresponding sections, where the condition name is properly linked.)
It's a minor issue, but also easy to fix. Thanks.
EDIT: Found another bunch of missing links: in the conditions list themselves. Again, the PHB appendix A has the proper links, but the same section of the basic rules is missing that link in a bunch of condition descriptions that reference the incapacitated condition: grappled, paralyzed, petrified, and stunned. For some reason, only unconscious is the exception.
In the basic rules version, all of the mentioned conditions except unconscious say "incapacitated (see the condition)" in plain text, with no link to the incapacitated condition; the unconscious condition says:
An unconscious creature is incapacitated, can't move or speak, and is unaware of its surroundings
In the PHB version on D&D Beyond, all of the other conditions properly link to the incapacitated condition, but still have the "(see the condition) parenthetical after it. And in the physical PHB itself, all of the mentioned conditions (including unconscious) have that parenthetical after them. If they are all properly linked on D&D Beyond, I assume the parenthetical is unnecessary - except maybe in the popup/popover that appears when you hover over a linked condition, since you can't exactly have nested popups.
(The missing period at the end of that bullet point from the unconscious condition description seems to be an error copied from the PHB itself - it's still missing from the unconscious condition description even in my relatively new PHB from earlier this year. However, oddly enough, the 2018 Basic Rules PDF doesn't have that error - there is a period at the end of the line there. An older version, Basic Rules v3.4, also has the period in the proper place.)
It's a very minor issue, but the grappling section of the basic rules have this line as of the 2018 errata:
However, the text doesn't link to the incapacitated condition. The Shoving section that follows has the same line, where it is properly linked.
(The PHB also has the same lines in the corresponding sections, where the condition name is properly linked.)
It's a minor issue, but also easy to fix. Thanks.
EDIT: Found another bunch of missing links: in the conditions list themselves. Again, the PHB appendix A has the proper links, but the same section of the basic rules is missing that link in a bunch of condition descriptions that reference the incapacitated condition: grappled, paralyzed, petrified, and stunned. For some reason, only unconscious is the exception.
In the basic rules version, all of the mentioned conditions except unconscious say "incapacitated (see the condition)" in plain text, with no link to the incapacitated condition; the unconscious condition says:
In the PHB version on D&D Beyond, all of the other conditions properly link to the incapacitated condition, but still have the "(see the condition) parenthetical after it. And in the physical PHB itself, all of the mentioned conditions (including unconscious) have that parenthetical after them. If they are all properly linked on D&D Beyond, I assume the parenthetical is unnecessary - except maybe in the popup/popover that appears when you hover over a linked condition, since you can't exactly have nested popups.
(The missing period at the end of that bullet point from the unconscious condition description seems to be an error copied from the PHB itself - it's still missing from the unconscious condition description even in my relatively new PHB from earlier this year. However, oddly enough, the 2018 Basic Rules PDF doesn't have that error - there is a period at the end of the line there. An older version, Basic Rules v3.4, also has the period in the proper place.)
Please fix these issues.