Foss apps that switches data off and turns 2G at the same time?

My oldish smartphone has 4G capabilities only on data but not on calls because it doesn't support Volte. That means, when people call me, they find an engaged tone as if I wasn't available. Manually forcing using 2G fixes the problem but then I can't use data.

Is there an app that saves me the time to go into settings, switch data off and force 2G or viceversa, forces 4G and switches data on? Probably not but who knows.

Thanks.