I have a data frame with 3 columns Column 1 - Created Column 2 - Resolved Column 3 - Issue Type

I'm trying to figure out how much time has passed between Resolved and Created (days, hours, minutes, and seconds). When I try to do the same, I always receive the error below. Could someone please assist in cleaning these data and resolving them?

Sample data in dataframe

df['Created'] = df['Created'].apply(parse)
df['Resolved'] = df['Resolved'].apply(parse)
print(df)

df['delta'] = df['Resolved'] - df['Created']
df