Translation:If you want we can speak slowly.
How do you want to use it? :? I can't imagine where it can be placed here.
Instead of якщо. Maybe it's just a thing in my language (Slovak). The Slovakian translation would then be: "Ako chcete, môžeme hovoriť pomaly." This would mean something like "Be as you want, we can speak slowly." But it doesn't sound so good in English and probably neither in Ukrainian.
«Як [Ви] хочете» would indeed mean 'be as you want' (the pronoun is very often dropped in this phrase), but I'm not sure it corresponds to the English sentence very well.
I can not give you a scientific explanation but sometimes they speak similar way here. Maybe it is an influence of western languages like Slovakian. So it can be "Як хочете/хочеш, [то] ..." which in this case corresponds to "якщо хочете/хочеш, [то] ...". But it's more likely a poetic/regional language. In modern Ukrainian "як" means mostly "how".