any tips on getting attention of the band/a manager?

I'm getting married next year, and my soon-to-be husband played and sang me Carin at the Liquor Store the first night he brought me back to his house. The National has been our constant soundtrack and will be more than one dance at our wedding. I'm trying to organize a wedding gift for him, and it's a bit of a pipe dream but a signed & dedicated copy of Sleep Well Beast from Matt/the band would be such an incredible gift. I've never tried to reach out to a band like this before, does anyone have any tips on the best way to get in touch with someone about this? Is it messaging the band directly on Instagram? DMs are also open if anyone has recommendations they'd like to send directly!