Learn Hardcore German: Deshalb verlängere ich sie sofort online und speichere die neue Bestätigung. - Therefore I renew it online immediately and save the new confirmation.

Deshalb is a sentence‐adverb (a conjunctive adverb) meaning “therefore” or “that’s why.” When you start a main clause with any element other than the subject (here Deshalb), German requires the finite verb to occupy the second position (Verb-Second or V2 word order). Placing Deshalb first emphasizes the causal link with whatever was said before.

Why does the verb verlängere come immediately after Deshalb?

In German main clauses the conjugated verb must be in position two. Since Deshalb fills position one, verlängere (the 1st-person-singular form of verlängern) comes in position two. The subject ich follows in position three.

What does the pronoun sie refer to, and why is it in the accusative?

Sie is the 3rd-person-singular feminine accusative pronoun (“her/it”). In context it probably refers back to a feminine noun mentioned earlier (for example die Versicherung or die Mitgliedschaft). Because verlängern is a transitive verb requiring a direct object, that object is in the accusative case.

Why is sie placed before the adverbs sofort online?

German word order often places pronoun objects before adverbials. So the sequence is:
1) finite verb (verlängere)
2) subject (ich)
3) pronoun object (sie)
4) time adverb (sofort)
5) manner/place adverb (online)

What role does online play here? Is it an adjective or an adverb?

Online is used adverbially, indicating the mode or manner of the action (“online/over the internet”). As an adverb, it doesn’t change form and follows the time adverb sofort.

In the second clause, why is there no subject before speichere?

When you coordinate two main‐clause verbs with und, you can drop the repeated subject. The subject ich is understood:
“Deshalb verlängere ich sie … und (ich) speichere die neue Bestätigung.”

Why is die neue Bestätigung in the accusative case?

Speichern (“to save”) is a transitive verb that takes a direct object. Die neue Bestätigung (feminine noun) is the thing being saved, so it appears in the accusative case with the article die unchanged (fem. nom. = fem. acc.).

Could I say Ich verlängere sie deshalb sofort online und speichere die neue Bestätigung instead?

Yes, you can move Deshalb to a later position:
“Ich verlängere sie deshalb sofort online …”
That puts the subject first and deshalb in third position. The nuance is slightly less emphatic on the reason; the original order stresses the causal link right away.

Why is the present tense used here for what sounds like a completed action?

In German, the present tense often covers near‐future or immediate actions, especially when the time adverb sofort (“immediately”) clarifies that it happens right away. You could use the perfect tense (habe verlängert, habe gespeichert) to report completed actions, but present is natural for “I now do this.”