When adding fruit or other adjuncts most of the time, you will need to use the custom fermentable field on the recipe creator. this is because fruit will add fermentables that may significantly affect the final ABV of your beverage.
You can usually find the brix (grams of sugar per 100ml) from a quick internet search for most fruit products. from here you can use the formula brix/100 * 45 to find the PPG. now that you have the PPG you can now add the amount and it will affect the OG and FG.
adding fruit will add colour to the beer, so add an EBC that is the approximation of the colour of the fruit. e.g. most berries are a red - pink therefore using an EBC of 28 should approximate the final colour of the beer.
the last thing to note is that when using fruit, often the sugars are well bound within the cell walls of the fruit. therefore, pectinase and other enzymes should be used to improve clarity and ensure the target ABV is reached.