\begin{table}
\centering
\begin{tblr}[         %% tabularray outer open
]                     %% tabularray outer close
{                     %% tabularray inner open
colspec={Q[]Q[]},
column{1}={halign=l,},
column{2}={halign=c,},
hline{4}={1,2}{solid, 0.05em, black},
}                     %% tabularray inner close
\toprule
& (1) \\ \midrule %% TinyTableHeader
x1             & \num{0.791}                  \\
& (\num{0.127})                \\
Num.Obs.       & \num{150}                    \\
R2             & \num{0.735}                  \\
R2 Adj.        & \num{0.714}                  \\
R2 Within      & \num{0.275}                  \\
R2 Within Adj. & \num{0.269}                  \\
AIC            & \num{192.8}                  \\
BIC            & \num{228.9}                  \\
RMSE           & \num{0.42}                   \\
Std.Errors     & by: fe1\textasciicircum{}fe2 \\
FE: fe1        & X                             \\
FE: fe2        & X                             \\
FE: fe3        & X                             \\
\bottomrule
\end{tblr}
\end{table} 
