Your husband was very generous in getting you such a lens, but he was either mis-advised or taken for a ride if he told the sales people what kind of camera you have. As Kevin has indicated, you cannot attach an RF lens to an EF body with an adapter, it is physically impossible. Best solution is to return the lens and get something more suitable - personally, I would recommend the Sigma 150-600 Contemporary unit, or if you can afford it the EF 100-400 MkII unit.
An alternative solution is to up the ante and get an R-series body. The cheapest body would be the RP camera, which is generally regarded as great value. If you want IBIS (In Body Image Stabilization) then something like the R6 would be the way to go. You CAN get adapters to connect your existing EF lenses to an RF mount and they work perfectly.
cheers, TREVOR
"The Amount of Misery expands to fill the space available"
"All the variety, all the charm, all the beauty of life is made up of light and shadow", Leo Tolstoy;
"Skill in photography is acquired by practice and not by purchase" Percy W. Harris
