  Recently Sun et al (Nature 621, 493 (2023)) reported on the discovery of
high-temperature superconductivity in highly-compressed
La$_3$Ni$_2$O$_{7-\delta}$. In addition to ongoing studies of the phase
structural transition, pairing mechanism, and other properties/parameters in
this highly-pressurized nickelate, here explore a possibility for the
electron-phonon pairing mechanism in the La$_3$Ni$_2$O$_{7-\delta}$. To do
this, we analyzed experimental data on temperature dependent resistance,
$R(T)$, and extracted pressure dependent Debye temperature, $\Theta_D$, for the
$Fmmm$-phase (high-pressure phase). Derived ballpark value is $\Theta_D(P = 25
GPa) = 550$ $K$. We also estimated the electron-phonon coupling constant,
$\lambda_{e-ph}(P=22.4 GPa) = 1.75$, for La$_3$Ni$_2$O$_{7-\delta}$ sample
exhibited zero-resistance transition. Performed analysis of XRD data showed
that the crystal lattice strain, $\epsilon(P)$, is higher in the $Fmmm$-phase
in comparison with the $Amam$-phase (low-pressure phase). Based on performed
$\epsilon(P)$ analysis, we proposed possible reason for the presence/absence of
the zero-resistance state in La$_3$Ni$_2$O$_{7-\delta}$.
