How to have R 4.1 on Debian 11? Debian 11 won't update

1. Debian 11 only updates to R 4.0.4. 2. I have packages that require at least R 4.1.0 to be installed. 4. I already tried adding the official R repository to the source list as the official website tells to do , but I get the following limitation. > sudo apt update > > 20 packages can be upgraded. Run 'apt list --upgradable' to see them. > > apt list --upgradable > > r-base-core/bullseye-cran40 4.3.2-1~bullseyecran.0 amd64 [upgradable from: 4.0.4-1] > > r-base-dev/bullseye-cran40 4.3.2-1~bullseyecran.0 all [upgradable from: 4.0.4-1] > > r-base/bullseye-cran40 4.3.2-1~bullseyecran.0 all [upgradable from: 4.0.4-1] > > r-cran-boot/bullseye-cran40 1.3-28.1-1~bullseyecran.0 all [upgradable from: 1.3-27-1] > > r-cran-class/bullseye-cran40 7.3-22-2~bullseyecran.0 amd64 [upgradable from: 7.3-18-1] > > r-cran-cluster/bullseye-cran40 2.1.4-1~bullseyecran.0 amd64 [upgradable from: 2.1.1-1] > > r-cran-codetools/bullseye-cran40 0.2-19-1~bullseyecran.0 all [upgradable from: 0.2-18-1] > > r-cran-foreign/bullseye-cran40 0.8.85-1~bullseyecran.0 amd64 [upgradable from: 0.8.81-1] > > r-cran-kernsmooth/bullseye-cran40 2.23-22-1~bullseyecran.0 amd64 [upgradable from: 2.23-18-1] > > r-cran-lattice/bullseye-cran40 0.22-5-1~bullseyecran.0 amd64 [upgradable from: 0.20-41-1+b1] > > r-cran-littler/bullseye-cran40 0.3.18-2~bullseyecran.0 amd64 [upgradable from: 0.3.12-1] > > r-cran-mass/bullseye-cran40 7.3-60-2~bullseyecran.0 amd64 [upgradable from: 7.3-53.1-1] > > r-cran-matrix/bullseye-cran40 1.6-1.1-1~bullseyecran.0 amd64 [upgradable from: 1.3-2-1] > > r-cran-mgcv/bullseye-cran40 1.9-0-1~bullseyecran.0 amd64 [upgradable from: 1.8-34-1] > > r-cran-nlme/bullseye-cran40 3.1.163-1~bullseyecran.0 amd64 [upgradable from: 3.1.152-1] > > r-cran-nnet/bullseye-cran40 7.3-19-2~bullseyecran.0 amd64 [upgradable from: 7.3-15-1] > > r-cran-rpart/bullseye-cran40 4.1.21-1~bullseyecran.0 amd64 [upgradable from: 4.1-15-2+b1] > > r-cran-spatial/bullseye-cran40 7.3-17-1~bullseyecran.0 amd64 [upgradable from: 7.3-13-1] > > r-cran-survival/bullseye-cran40 3.5-7-1~bullseyecran.0 amd64 [upgradable from: 3.2-7-1] > > r-recommended/bullseye-cran40 4.3.2-1~bullseyecran.0 all [upgradable from: 4.0.4-1] > > sudo apt upgrade > > The following packages have been kept back: > > r-base r-base-core r-base-dev r-cran-boot r-cran-class r-cran-cluster r-cran-codetools r-cran-foreign r-cran-kernsmooth r-cran-lattice r-cran-littler > > r-cran-mass r-cran-matrix r-cran-mgcv r-cran-nlme r-cran-nnet r-cran-rpart r-cran-spatial r-cran-survival r-recommended >