  Intuitively, doping represents one of the most promising avenues for
optimization of best prospect superconductors (SC) such as conventional
high-pressure SCs with record critical temperatures. However, doping at high
pressure (HP) is very challenging, and there is not a proved route to achieve
it in a controlled fashion. Aided by computing simulations, we show that it may
be plausible to start by alloying primary materials and subsequently
incorporate high ratios of hydrogen at moderates pressures ($\approx$1.5 Mbar).
Our theoretical results evidence the possibility to tune the electronic
structure of LaH$_{10}$, increase the density of states at the Fermi level by
doping of various elements and hence change their superconducting properties.
We found aluminium to increase the occupation at the Fermi level by more than
30 %. Incorporation of other elements such as Si, Ge, H, Ir, Ca, and others
with a varying percentage also play in favour to tune the electronic structure.
More importantly, these predictions lie in experimentally attainable doping
levels. Also, for the first time, we shed light on how the formation of defects
and vacancies influence on the electronic structure of a HP-hydride
superconductor. The concepts presented in this work can be extended to other
high-pressure, hydrogen-based superconductors such as H$_3$S. Arguably, doping
is one of the promising paths to reach room-temperature superconductivity, a
Holy grail of condensed matter physics.
